Vladimir Putin has ordered a state of emergency after 20,000 tonnes of diesel fuel spilled into a river inside the Arctic Circle. The spill occurred when a fuel reservoir at a power plant near the city of Norilsk collapsed on Friday. The plant is operated by a division of Nornickel, whose factories in the area have made the city one of the most heavily polluted places on Earth. During a video conference on Wednesday that was broadcasted on television, Putin lambasted the head of the Nornickel subsidiary that owns the power plant, NTEK, after officials said the company failed to report the incident. “Why did government agencies only find out about this two days after the fact? Are we going to learn about emergency situations from social media? Are you quite healthy over there?” the Russian president told Sergei Lipin, the head of NTEK. Nornickel said NTEK had reported what happened in a “timely and proper” way. The governor of the Krasnoyarsk region, where Norilsk is located, told Putin he only learned of the real situation on Sunday after “alarming information appeared in social media”. Putin said he agreed that a national state of emergency was needed in order to call in more resources for the cleanup effort. Russia’s investigative committee, which deals with major crimes, announced it had launched three criminal investigations into the accident and detained a power plant employee. Alexei Knizhnikov of the World Wildlife Fund said the environmental group was the one who alerted cleanup specialists after confirming the accident through its sources. “These are huge volumes,” he said. “It was difficult for them to cover it up.” The volume of the spill is vastly larger than the 2007 Kerch spill, which involved 5,000 tonnes of oil, Knizhnikov said. At the time the spill in the Black Sea strait was the largest of its kind for Russia and required intervention of the military and hundreds of volunteers. Knizhnikov said diesel fuel is lighter than oil, so it was likely to evaporate rather than sink but was also “more toxic to clean up”. The Ambarnaya River that bore the brunt of the spill will be difficult to clean up because it is too shallow to use barges and the remote location has no roads, officials told Putin. Russia’s environment minister, Dmitry Kobylkin, said he thought burning the fuel, which some are suggesting, was too risky. “It’s a very difficult situation. I can’t imagine burning so much fuel in an Arctic territory … such a huge bonfire over such an area will be a big problem.”