Ukraine has struck two oil refineries in Russia, Ukrainian President Volodymyr Zelenskyy said Thursday.

In a social media post, Zelenskyy said Ukraine’s Defence Forces targeted the Slavneft-Yanos refinery in Yaroslavl and the Bashneft-Novoil refinery in Russia’s Bashkortostan region.

Earlier, reports said thick black smoke was seen rising from the area of the Yaroslavl refinery following Ukrainian drone attacks.

Yaroslavl Governor Mikhail Evraev said Ukrainian drones targeting the region had been destroyed, but falling debris set three houses on fire.

Zelenskyy also said Ukrainian forces attacked two Russian military patrol boats and vessels linked to Russia’s so-called shadow fleet in the Black Sea.