MOSCOW (Reuters) -Russia said on Wednesday that its air defences had shot down at least 232 Ukrainian drones over various Russian regions, including some approaching Moscow where the capital's airports were briefly shut down to ensure the safety of flights.

While Russia, Ukraine, the United States and European powers consider the sequencing of a possible end to the more than three-year conflict in Ukraine, the drone war continues and fighting is intensifying in some areas of the front.

Russia's Defence Ministry said it had destroyed at least 232 Ukrainian drones, mostly over Russia's western regions bordering Ukraine, but also some approaching Moscow, a city which along with the surrounding area has a population of 21 million people.

Moscow Mayor Sergei Sobyanin said three drones had been downed en route to the capital where three major airports briefly stopped flights before resuming operations.

There were no reports of casualties, but Ukraine's military said that its drones had hit the Bolkhovsky Semiconductor Devices Plant, a semiconductor devices plant in the Oryol region that it said supplied Russian fighter jet and missile producers.

The war in Ukraine, which has left hundreds of thousands of people dead, has become a crucible of drone innovation with both sides fielding swarms of drones far behind the front lines in an attempt to disrupt production facilities.

Moscow and Kyiv have both sought to buy and develop new drones, deploy them in innovative ways, and seek new ways to destroy them - from farmers' shotguns to electronic jamming.

Soldiers have reported a visceral fear of drones and both sides have used macabre footage of fatal strikes in their propaganda, with soldiers shown being blown apart in toilets or running from burning vehicles.

Russia's Defence Ministry said its forces were advancing at key points along the front and pro-Russian war bloggers said Russia had pierced the Ukrainian lines between Pokrovsk and Kostiantynivka in the Donetsk region of eastern Ukraine.

Reuters could not verify that assertion.

President Vladimir Putin on Tuesday visited the western Kursk region for the first time since Russian forces ejected Ukrainian troops from the area last month.

Putin sent tens of thousands of soldiers into Ukraine in February 2022 and Russia now controls just under one fifth of the country.