In the hours before Ukrainian soldiers stormed across Russia's western border, there was no sign from Moscow that anything was amiss.
At midnight at the start of Aug. 6, the Russian defense ministry posted good news: more than 2,500 members of the regiment responsible for the capture of a town in eastern Ukraine would receive state awards for heroism.
Later that morning, as Ukraine began the biggest invasion of Russia since World War Two, the ministry published video showing General Valery Gerasimov, commander of the Russian war effort, visiting a different combat zone, also in Ukraine. He heard reports from commanders and set "tasks for further actions," it said.
The footage did not specify the exact time of the visit, but revealed no concerns, or knowledge, of the events unfolding in Russia's western Kursk region that threatened to upset Gerasimov's plans and shift the course of the two-and-a-half-year war.
Panic spread quickly among local Russian residents in the early hours of the assault, despite repeated attempts by authorities to assure them that everything was under control, according to a timeline by Reuters of the first two days of the incursion, based on public statements, social media posts and analysis of video footage.
The idea that Ukraine could turn the tables on Russia and burst onto the territory of its much bigger neighbor seemed unthinkable to most observers before last week. The shock operation has raised questions about the effectiveness of Russia's surveillance, as well as the caliber of its border fortifications and the forces guarding them.
"The Russians had a complete intelligence failure here," French military expert Yohann Michel, research fellow at the IESD institute in Lyon, said in an interview.
With Ukraine's forces retreating in eastern Ukraine, one of the most strategic sectors of the front line, Moscow may well have assumed that Kyiv would not make a high-stakes gamble that even now it is far from clear will pay off, Michel said.
"I would understand if it was difficult for the Russians to think something that big could happen," he said.
Ukrainian goals in Kursk include distracting Russian forces from the front line in the eastern region of Donetsk. Instead, fighting has intensified in that region in recent days, and the risks for Ukraine are rising as it tries to hold ground in Kursk.
A Russian member of parliament and former military officer, Andrei Gurulyov, said in a television interview two days after the incursion that Russian military leaders had been warned in a report about a month beforehand that there were signs of preparations for a Ukrainian attack, but it was not heeded.
The Russian defense ministry did not reply to requests for comment. Ukraine's armed forces declined to comment about the ongoing operations, and the U.S. State Department, Pentagon and White House did not immediately respond to questions.
It was not until the afternoon of the following day, Aug. 7, that President Vladimir Putin and Gerasimov, his armed forces chief of staff, made their first public remarks on the Kursk events, which the Kremlin leader called "another major provocation" by Ukraine.
Gerasimov, fresh from his ill-timed trip, told Putin in the televised comments that Russian forces had "stopped" a force of up to 1,000 Ukrainian soldiers from thrusting deep inside the Kursk region.
Michel, the military analyst, said it was unclear whether Gerasimov was misinformed by his own subordinates, or whether he felt compelled to deliver good news to Putin in front of the TV cameras.
Russian officials in such staged settings "say what they think the boss wants to hear or to see in public at that specific moment", Michel said.
It took nearly 12 hours from the time of the incursion, which Gerasimov stated as 5:30 a.m. on Aug. 6, for the defense ministry to publicly acknowledge that Ukraine had attacked the border, let alone broken through it.
It was left to Kursk's acting regional governor, Alexei Smirnov, only months into the job, to fill the communications vacuum and try to coordinate with the multiple defense and security agencies responsible for protecting the border.
In the first of many Telegram posts on Aug. 6, Smirnov issued missile warnings at 1:51 and 3:11 a.m. local time, urging residents to take cover. At 3:15, he said that air defenses had knocked out three incoming Ukrainian drones. At 6:16, 11 more.
Regions either side of the border have long grown used to tit-for-tat missile and drone attacks. But strikes against the Kursk region, recorded by Smirnov in Telegram posts, had been more than usually persistent for the previous 10 days. Among the targets hit were oil depots, power substations and, according to the Ukrainian military, a storage facility for weapons and military equipment.
From about 5 a.m., alarm began to spread on social media. Locals posted that shelling in Sudzha, a Russian town on the border, had been going on for three hours.
"What's going on with the lights? I've got no light or water," said a woman posting as "Ekaterina Picasa." A user called Denis reported nine explosions in Korenevo, about 16 miles from the border.
Reuters made multiple attempts to contact residents via social media, but these were ignored or blocked.
A stream of posts appeared in "Native Sudzha," a community channel on the social network VKontakte, but it was not clear whether the information was from official sources. "We advise people to leave the town," said one such message at 7:34 a.m. People were warned to beware of drones and watch out for unexploded shells.
By 8:15 a.m. Native Sudzha was reporting "active fighting on the border itself." But a widely read Russian war blog was dismissive.
The "Two Majors" Telegram channel, followed by more than a million people, said a small group of "the enemy" had managed to get only as far as 300 meters inside Russia and was "being destroyed." It suggested the operation was being staged by Ukrainian "TikTok units" as a media exercise.
Ukraine's government has said little about the planning of the incursion.
In May, shortly after Russian troops crossed the border and seized territory in the nearby Kharkiv region, Ukraine's military intelligence chief publicly warned of small groups of Russian forces gathering around the Sudzha area and said Moscow had planned an operation into Ukraine's Sumy region from there.
Reuters could not independently verify whether Russia had been preparing an offensive into Sumy.
On Friday, Ukraine's paratrooper corps said its fighters spent the first hours of the operation demining, breaching the border and destroying defensive lines, using aviation and artillery.
"Careful preparation, planning, surprise, fighting spirit and informational silence became decisive in the initial stage of the operation," the Airborne Assault Troops said in an online post.
A Ukrainian soldier called Dmytro, 36, said he initially thought the Ukrainian army's build-up was to prevent a Russian cross-border raid.
Instead, he found himself supporting the advance toward the border crossing near Sudzha after the assault units moved in, he said in an interview, giving his only first name in line with military protocol.
"We worked to preempt them, and they did not see this coming at all," he said.
Just after 10 a.m., Governor Smirnov confirmed for the first time that Ukraine had attempted an incursion but said Russian soldiers and border guards of the FSB security service had "prevented" the border from being breached.
It was the first of numerous statements that were to be quickly disproved by events.
Just before noon, the defense ministry published its video of Gerasimov visiting Russian forward positions in Ukraine. On events in Kursk, it was silent.
So too was the Kremlin, with spokesman Dmitry Peskov on a summer break and reporters left without his usual daily briefing. As of Aug. 16, 10 days later, he had not returned to work.
"Tell me please, is it true that Ukrainian tanks have broken through to Sudzha and Darino?" a user, "Nestik," posted on Telegram.
Smirnov posted that help was being provided to residents of areas that had been struck overnight by missiles and drones. "The situation is under control," he wrote at 12:46 p.m.
About an hour later, Russian news agencies published the first word from the central authorities about the situation. It was from the FSB, saying Russia had "repelled an armed provocation."
By now, however, an exodus was under way. Sudzha residents were "leaving en masse", a woman called Anna said on Telegram.
"Of course. Everyone wants to live," someone replied.
In the chaos, some were left behind. A search network, Liza Alert, said it has posted over 100 "missing" notices for people who have disappeared since Aug. 6, including many pensioners in their 70s and 80s.
Smirnov's predecessor as governor, Roman Starovoit, had repeatedly told the public that Russia had boosted its border fortifications in Kursk region.
In December 2022, he posed in a snowy field beside pyramid-shaped "dragon's teeth" anti-tank defenses. The following month, he wrote: "Right now the risk of an armed invasion of the territory of Kursk region from Ukraine is not high. However, we are constantly working to strengthen the region’s defense capabilities."
Yet last fall Ukraine's National Resistance Center, created by the special operations forces, said in an online post that reconnaissance showed "almost all the strongholds are deserted of personnel and equipment" along the border with Kursk, and said corruption was a factor.
The video published by Ukraine's paratroopers showed columns of armored vehicles pouring in through rows of dragon’s teeth, part of fortifications in Kursk that Russia media outlets have said cost $168 million.
Pasi Paroinen, an analyst with Finland's Black Bird Group, said the video appeared to show mine-clearing line charges blowing paths through minefields, dozer blades on armored vehicles used to clear paths through the dragon's teeth and bridging vehicles to cross ditches and small rivers.
"It's clear that substantial amounts of different engineer equipment were prepared and used," said Paroinen, who studies publicly available footage from the Russia-Ukraine war.
Brady Africk, a U.S. analyst mapping Russia’s defenses, said those in Kursk region had fewer anti-vehicle ditches, obstacles and fighting positions when compared to Russian positions in occupied southern Ukraine, where a Ukrainian counteroffensive stalled last summer.
"It was likely easier for Ukrainian forces to progress around and through Russia's fortifications in the region, especially if they were manned by fewer or poorly trained personnel," he said.
Responsibility for defending the Russian border is shared between regular troops, FSB border forces and the national guard. Governor Smirnov was apparently referring to these various agencies when he said on mid-afternoon of the first day that he had met with "representatives of the security structures."
Already, he was backtracking from his initial line that they had prevented the border from being pierced. "The situation in the border area remains difficult, but our defenders are successfully working to destroy the enemy," Smirnov said.
At 5:05 p.m., the defense ministry mentioned the incursion for the first time and said Russia had transferred reserves to the area.
"Troops covering the state border, together with units of the border troops of the FSB of Russia, are repelling the attacks and inflicting fire on the enemy in the area of the state border and on its reserves in the Sumy region (of Ukraine)," it said.
At the briefing on Aug. 7, Gerasimov told Putin: "The operation will end with the smashing of the enemy, and (Russian forces) reaching the state border."
Ten days later, with more than 100,000 Russians displaced and Ukraine claiming control of more than 390 square miles of Kursk region, Moscow's forces are still far from achieving that goal.
