A Ukrainian drone attack caused a major fire at a Russian oil refinery in ‌the city of Tuapse on Tuesday, officials said, in the third attack on the Black ​Sea port in less than two weeks.

Ukraine's military confirmed it had carried out the attack, the latest in an intensified series of strikes designed ⁠to disrupt Russia's oil industry and slash revenues that help Moscow to fund the war in ​Ukraine.

Images on social media showed dense black smoke rising from the direction of the refinery. The ⁠state consumer watchdog told people to stay indoors and keep windows closed.

Following a previous attack on April 20, black rain fell on the town, leaving an oily residue.

The refinery halted production on April 16 because of drone damage ‌to the port that made it impossible to ship its production, industry sources told ​Reuters. At least ‌three people have been killed in the strikes, according to officials, and one of them led to an oil spill at sea.

Tuapse is ‌also a popular beach resort.

The head of the Tuapse district, Sergei Boyko, on Tuesday ordered people living near the refinery to evacuate by bus to a local school.

On social media, some residents ‌expressed anger, demanding to know why ⁠air defenses had not been strengthened to prevent a third successive attack.

In a local chatroom, some people complained that authorities in ⁠Moscow ⁠were indifferent to their plight.

Kremlin spokesman Dmitry Peskov said authorities were "working intensively" to combat Ukrainian drone strikes.

At his daily briefing ‌with reporters, Peskov was asked if and when an environmental emergency would be declared, and whether people should be evacuated to avoid exposure to toxic emissions.

He said that measures were being taken at the appropriate level, ‌and that ​he had nothing further to ‌add.

Ukraine has stepped up its strikes on Russian energy targets since March, with U.S.-brokered talks on the war on pause and Washington mainly focusing on the Iran war.

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