Russia launched an unusually large drone attack on Ukraine overnight into Tuesday, shortly before Moscow's representatives opened talks with a U.S. delegation in Saudi Arabia on ending Russia's three-year full-scale invasion of Ukraine.

Residents posted videos on social media purportedly showing a large blaze at the refinery. Sounds of explosions were reported at around 2:45 a.m. local time.

An large-scale overnight Russian drone attack hit a residential building in the city of Dolynska in central Ukraine, injuring a mother and her two children and forcing evacuations from 38 apartments,

Beyond Ukraine, the meeting — attended by U.S. Secretary of State Marco Rubio, Russian Foreign Minister Sergey Lavrov and other senior officials — had been expected to focus on thawing relations between the two countries, whose ties have fallen to their lowest level in decades.

Regional Governor of Samara in Russia, Vyacheslav Fedorishchev, on Wednesday said Ukraine launched an overnight attack on an oil refinery in the city of Syzran. “Emergency services are working on the territory of the enterprise.

On the night of February 17, drones belonging to the Security Service of Ukraine (SSU) and Special Operations Forces (SSO) attacked two critical enterprises in Russia's Krasnodar Krai, according to RBC-Ukraine's source at the Security Service of Ukraine.

Ukrainian drones, operated by the Special Operations Forces (SSO) and Security Service of Ukraine (SBU), hit the Ilsky Oil Refinery in Krasnodar Krai and the Kropotkinskaya oil pumping station in the Kavkazsky District of Kuban overnight on Feb.

The refinery is one of the key facilities of its kind in the southern part of the country. Read also: Drones hit oil refinery in Russia's Krasnodar Krai, governor confirms damage "Its processing capacity is approximately 6.