Heavy snow since late Sunday has delayed flights, closed highways and caused casualties in northwest China's Xinjiang Uygur Autonomous Region.

The snow had delayed or canceled 122 flights from and to Urumqi, capital of the region, leaving more than 4,000 passengers stranded at the Urumqi airport, an airport official said late Monday.

Food and water had been provided to the stranded passengers. Flights began to resume since 7 p.m. Monday.

Nine avalanches occurred on the national highway section in Ili Kazak Autonomous Prefecture, leaving one dead and two injured.

More than 1,000 passengers in 150-odd vehicles had been stranded on the highway in the wake of the avalanches. Traffic began to resume after more than 100 rescuers were sent to the scene.

The snow had affected more than 1.6 million people, killing four of them and injuring 623 others, said an official of the regional civil affairs department.

The direct economic lost was estimated at 345.3 million yuan ( 50.8 million U.S. dollars).

More than 65 million yuan has been provided as disaster relief by the regional government. The Red Cross Society of China has also provided quilts, tents and funds, with a combined value of 560,000, as disaster relief for Xinjiang.