A Ukrainian ​drone attack caused a major fire at a Russian oil refinery in the city of Tuapse on Tuesday, ‌officials said, in what Russian President Vladimir Putin described as evidence of increased Ukrainian attacks on civilian targets.

It was the third attack on the Black Sea port in less than two weeks.

Ukraine's military confirmed it had carried out the strike, the latest in a series designed to disrupt Russia's oil industry and ​slash revenue that helps Moscow fund the war in Ukraine.

Putin, in comments broadcast on Russian television, said, "Drone strikes against civilian infrastructure ​are becoming more frequent."

"The latest example is the strikes against energy facilities in Tuapse, which could potentially ⁠cause serious environmental consequences," he said.

Putin said regional Governor Veniamin Kondratyev had reported there were no major threats. "It seems there are no ​serious dangers, and people are managing to deal with the challenges they face on the ground," he added.

The Kremlin accused Ukraine of exacerbating a global ​oil shortage by targeting storage facilities containing oil intended for export.

Ukrainian foreign ministry did not immediately respond to a request for comment on Moscow's ‌accusations. In ⁠the past, President Volodymyr Zelenskyy has said that Russian exports were not significant enough to affect global market prices.

Ukraine ​has stepped up its attacks on Russian energy targets since March, with US-brokered peace ​talks on pause and Washington mainly focusing on the Iran war.

The Tuapse refinery has annual production capacity of about 12 million metric tonnes, or 240,000 barrels per day, ​turning out naphtha, diesel, fuel oil and vacuum gasoil.