The leader of a Siberian region has declared Friday a non-working day and urged residents to stay at home as smoke from raging forest fires raised health concerns. Aisen Nikolayev, the head of Yakutia, Russia’s largest and coldest region, which has been hard-hit by wildfires this year, said on Thursday that the day off would apply to the regional capital, Yakutsk, and several other districts. In recent years wildfires have ripped across Russia’s vast territory at an unprecedented scale that experts blame on climate change, negligence and underfunded forestry management services. Nikolayev said in remarks carried by the RIA Novosti news agency: “Smoke from the fires has an extremely negative effect on people’s well-being. In order to minimise these consequences today I signed a decree declaring tomorrow a non-working day for 11 municipalities.” Nikolayev recommended that residents spent the day at home. Yakutsk airport was experiencing delays on Thursday with flights being cancelled or postponed due to poor visibility caused by the smoke. Russia’s president, Vladimir Putin, this week ordered reinforcements to fight the Siberian fires and sent the head of the emergencies ministry to Yakutia to oversee the operations there. In the vast and sparsely populated region blazes have so far burned through more than 9.2m hectares (22.7m acres), an area the size of Portugal, according to Russia’s forestry agency. Local firefighters told AFP that they lacked the people, equipment and resources to deal with the scale of the wildfires. Critics have pointed to a 2015 law that allows regions to ignore blazes if the cost of fighting fires outweighs the expected damage, saying the legislation provides cover for authorities to avoid fighting wildfires. The US space agency Nasa over the weekend said its satellite images showed wildfire smoke from Yakutia moving on to the north pole, calling it a first in history.