Russia-appointed officials in Moscow-occupied Crimea announced a regional emergency on Saturday, as oil was detected on the shores of Sevastopol, the peninsula’s largest city.

Fuel oil spilled out of two storm-stricken tankers nearly three weeks ago in the Kerch Strait, close to eastern Crimea — some 250 kilometers (155 miles) from Sevastopol, which lies on the southwest of the peninsula.

“Today a regional emergency regime has been declared in Sevastopol,” regional Gov. Mikhail Razvozhaev wrote on Telegram.

Oil was found on four beaches in the region and was “promptly eliminated” by local authorities working together with volunteers, Razvozhaev said.

“Let me emphasize: there is no mass pollution of the coastline in Sevastopol,” he wrote.

Razvozhaev’s announcement came after authorities in Russia’s southern Krasnodar region announced a region-wide emergency last week, as the fuel oil continued washing up on the coastline 10 days after one tanker ran aground and the other was left damaged and adrift on Dec. 15.

Krasnodar regional Gov. Veniamin Kondratyev said Friday that more than 5,000 people were still working to clean up the spill.

More than 86,000 tons of contaminated sand and soil have been removed along the region’s shoreline since the original spill, he wrote on Telegram.

On Dec. 23, the ministry estimated that up to 200,000 tons in total may have been contaminated with mazut, a heavy, low-quality oil product.

Russian President Vladimir Putin has called the oil spill an “ecological disaster.”

The Kerch Strait, which separates the Russia-occupied Crimean Peninsula from the Krasnodar region, is an important global shipping route, providing passage from the inland Sea of Azov to the Black Sea.

It has also been a key point of conflict between Russia and Ukraine after Moscow annexed the peninsula in 2014. In 2016, Ukraine took Moscow to the Permanent Court of Arbitration, where it accused Russia of trying to seize control of the area illegally. In 2021, Russia closed the strait for several months.

Mykhailo Podolyak, an adviser to the head of Ukrainian President Volodymyr Zelenskyy's office, described the oil spill last month as a “large-scale environmental disaster” and called for additional sanctions on Russian tankers.