The heaviest snowfall in more than a decade has left at least 21 people dead in Iran — some buried under avalanches, some frozen to death and others killed in traffic accidents, state media reported Monday.

As much as 22 inches of snow has fallen in areas of northern and central Iran since Saturday, said meteorologist Ali Abedini. The storm has forced schools and government offices to close, blocking major roads and leading to the cancellation of all domestic and international flights.

"At least 21 people have been killed and 88 others injured ... as a result of heavy snow," state-run radio reported. "Some died of the severe cold, some were buried under avalanches and others died after their cars overturned on snow-covered roads."

The cold weather has caused problems for residents in western Iran, with about a dozen towns suffering from gas cuts due to a surge in demand and a cut in gas exports from Turkmenistan.

Government officials have urged citizens to reduce their notoriously high consumption of gas to ensure there are no further cuts or shortages.

Authorities have also urged Iranians to cancel unnecessary travel and warned that the snowfall would continue in the coming days.