Ukraine pressed on with a major cross-border incursion into Russia yesterday, also launching a significant air attack on a Russian airfield hundreds of kilometres behind the front lines.

The Ukrainian offensive into Russia's western Kursk region, launched Tuesday, appears to be the most significant attack on Russian soil since Moscow invaded in February 2022.

Russia said around 1,000 Ukrainian troops and more than two dozen armoured vehicles and tanks were involved in the initial attack, though it has since claimed to have destroyed many more pieces of hardware.

Moscow said yesterday it was moving more troops and weapons to the Kursk region.

Kyiv has not officially taken responsibility for the operation, but Ukrainian President Volodymyr Zelensky said in his evening address on Thursday that Russia needed to "feel" the consequences of its invasion.

Ukraine said yesterday it had carried out a massive air strike on a Russian military base in the Lipetsk region, around 280 kilometres (175 miles) from the Russia-Ukraine border.

The local Russian governor Igor Artamonov reported a "massive" drone attack overnight and Russian state news agencies said the airfield was on fire.

"Last night, the Ukrainian Defence Forces attacked the Lipetsk airfield," Ukraine's General Staff said in a post on Telegram.

It said it had struck "warehouses containing guided aerial bombs and a number of other facilities" and that a "massive fire broke out" with "multiple detonations."

Artamonov cancelled several public events in the region and issued evacuation orders for districts close to the air base.

Russia's defence ministry said it destroyed 75 Ukrainian drones overnight, including 19 over the Lipetsk region and seven over Kursk, where Ukraine's four-day incursion has focused.