Ukraine launched a wave of long-range drones against targets deep inside Russia on Tuesday, Russian officials said, hitting at least two oil facilities in the attack on eight regions of Russia in the latest display of Kyiv’s expanding drone capacity.

Also Tuesday, soldiers who Kyiv officials say are Russian volunteers fighting for Ukraine reported to have crossed the border into Russia, as they have several times during the war. Russia said it had beaten back attempted incursions, but it wasn’t possible to verify either side’s claims and the reports of border fighting were murky.

Alleged incursions reported occasionally during the war are the subject of claims and counterclaims, as well as disinformation and propaganda.

One Ukrainian drone struck and set ablaze an oil refinery in the Nizhny Novgorod region, according to regional governor Gleb Nikitin. That region is located some about 775 kilometers (480 miles) from the Ukraine border.

In another deep strike, a drone was shot down in the Moscow region, Moscow mayor Sergei Sobyanin said. Though it was brought down well south of the city center, the drone was close to Zhukovsky Airport, one of Mocow’s four international airports.