MOSCOW (AP) — Moscow came under one of the largest attacks by Ukrainian drones since the start of fighting in 2022, Russian authorities reported Wednesday, saying they destroyed all of those headed toward the capital.

The drone attacks come as Ukrainian forces are continuing to push into Russia’s western Kursk region. In the past week, they have also struck three bridges, several airfields and an oil depot in a sign they are not letting up on their attacks.

“This was one of the biggest attempts of all time to attack Moscow using drones,” Moscow Mayor Sergei Sobyanin said on his Telegram channel. He said strong defenses around the capital made it possible to shoot down all the drones before they could hit their intended targets.

Russia said it downed 45 Ukrainian drones overnight, including 11 over the Moscow region. There was no independent information to verify those figures.

Some Russian social media channels shared videos of drones apparently being destroyed by air defense systems, which then set off car alarms.

Ukrainian drone strikes have brought the fight far from the front line into the heart of Russia, targeting the Russian capital and second city St. Petersburg, and an airport in Western Russia, according to Russian officials.

Since the beginning of this year, Ukraine has stepped up aerial assaults on Russian soil, targeting refineries and oil terminals to slow down the Kremlin’s assault.

A fire at an oil depot targeted by Ukraine burned for the fourth day Wednesday in Rostov, a region in southwestern Russia that borders Ukraine. Priests from the Russian Orthodox Church held a prayer service for injured firefighters as dark plumes of smoke rose in the distance at the oil depot in Proletarsk, according to a photo shared on social media by the Volgodonsk diocese.

Ukraine's daring land incursion into Russia has raised morale in Ukraine with its surprising success and changed the dynamic of the fighting and raised the morale of Ukrainians. But it is also a risky move. Ukrainian forces were already badly stretched, with active hostilities taking place along more than 970 kilometers (600 miles). The gains in Kursk come as Ukraine continues to lose ground in its eastern industrial region of Donbas.

The Russian state news agency Tass reported that 31 people had died since Ukraine’s attack on Russia began Aug. 6, figures which are impossible to verify. It said 143 people had suffered injuries, of whom 79 were hospitalized, including four children.

A Ukrainian drone dropped an explosive device on a car in the Bolshesoldatsky area of the Kursk region, slightly northeast of the town of Sudzha, the acting governor Alexei Smirnov said. One woman was killed on the spot and two others were hospitalized, he said.

Russia’s Central Electoral Commission announced that local elections in six districts and one city of the Kursk region scheduled for Sept. 8 will be postponed and rescheduled when voters' safety can be guaranteed.

Maria Zakharova, spokeswoman for the Russian Foreign Ministry, said Ukraine’s attack on Kursk has ended “any possibility” of peace negotiations.

“Who will negotiate with them after this, after the atrocities, the terror that they are committing against peaceful residents, the civilian population, civilian infrastructure and peaceful facilities,” she said at a briefing Wednesday in Moscow.

Ukraine said it was respecting the Geneva Conventions, the international humanitarian rules of war.

Ukraine’s Interior Minister Ihor Klymenko said the Ukrainian military established an office in the Kursk region to provide humanitarian and medical aid to the local population. More than 90% of the Russian civilians who stayed in territories of the Kursk region currently controlled by Ukraine are age 60 and older, he said.

“We have no right to leave them there to die," Klymenko said, according to the Ukrinform national news agency.

Ukraine’s attacks on three bridges over the Seym River in Kursk could potentially trap Russian forces between the river, the Ukrainian advance and the Ukrainian border. Already they appear to be slowing down Russia’s response to the Kursk incursion.

Ukrainian forces appear to be striking Russian pontoon bridges and pontoon engineering equipment over the Seym in an area west of the Ukrainian advance point, the Washington-based Institute for the Study of War said Tuesday.

Satellite photos from Planet Labs PBC analyzed Wednesday by The Associated Press showed a significant fire on the Seym near the village of Krasnooktyabrskoe.

The blaze appeared on the northern bank of the river on Tuesday, with another fire seemingly in the village itself. Such fires are common after strikes and often signify where ongoing front-line combat is taking place.

The Russian Defense Ministry said its forces had thwarted attack attempts by Ukrainian assault groups in the Kursk region, according to a report from Tass. Ukraine’s armed forces saw more than 45 soldiers killed or wounded over the past 24 hours and two were captured while attempting to attack the Kursk region, Tass said. There was no independent confirmation of those numbers and no comment from the Ukrainian side.