Russia declared a federal state of emergency in the Krasnoyarsk region as pollution from a diesel spill in the Arctic city of Norilsk drew comparisons with the Exxon Valdez accident off Alaska in 1989.

The state of emergency was announced late Wednesday after being approved by President Vladimir Putin. Greenpeace called the accident the largest ever in the Arctic Circle region. On May 29, 20 000 t of diesel spilled from a reservoir owned by MMC Norilsk Nickel’s power and utility unit.

The fuel has polluted land and local rivers that drain into a lake that’s linked to the Kara Sea. That lake is already affected, Kommersant newspaper reported, citing a spokesman at the Federal Agency for Fishing.

Emergency Situation Minister Yevgeny Zinichev flew to the area on Thursday, after talks with Putin and representatives of Nornickel. The company said on Tuesday that the accident could have resulted from melting permafrost damaging the base of the fuel reservoir.

Scientists have warned for years that the thawing of once permanently frozen ground covering more than half of Russia is putting buildings, pipelines and other infrastructure at risk. The rate of warming in the Arctic is twice as fast as the rest of the world.

Putin finally decided to ratify the 2015 Paris climate accord this year, after previously challenging the widely held assertion that global warming is due almost exclusively to human activity.

The President was unhappy with the handling of the accident after Krasnoyarsk Governor Alexander Uss said he only learned about the scale of the incident from social media two days after it occurred. Nornickel said the authorities were informed about the accident immediately.

The company called in a specialist clean-up team from Murmansk, which has fenced off the spill and is pumping out the fuel. The team has collected 80 t of fuel from the water surface and 100 t from the ground, Nornickel’s press service said.

The state of emergency will allow the best available federal resources to be deployed, Zinichev has said.

United Co. Rusal, which owns 28% of Nornickel, has called for an unscheduled board meeting to discuss the spill.