(Reuters) - Hopes faded on Sunday for survivors of one of Nepal's worst mountain disasters as villagers joined an intensive search by troops and government officials for as many as 40 people missing after an unseasonal blizzard killed 39.

More than 500 people have been rescued from a route popular with foreign adventure tourists that circles Annapurna, the world's tenth-tallest peak, among them 230 foreigners.

Rescuers turned to villagers familiar with the rugged, snow-clad terrain in the hunt for trekkers stranded in isolated areas after the tail end of a cyclone that hit neighboring India last weekend triggered the snow and avalanches. 

"We are not clear where the missing people are and whether they are safe or not safe," Yadav Koirala, the chief of Nepal's disaster management authority, told Reuters in Kathmandu, the capital.

"We can only hope and pray that they are not dead."

Since Wednesday, rescue teams have recovered 30 bodies and identified nine more from the air.

"The snow is very thick and the rescue teams are finding it difficult to pull the nine bodies out," said K.P. Sharma, an administrator in Dolpa, a district of glaciers and ravines.

Army helicopters continued to search for survivors on parts of the trail at an altitude of more than 5,000 meters (16,400 feet). Solders fanned out through some of the most treacherous terrain where helicopters cannot land.

The dead include Canadian, Indian, Israeli, Japanese, Nepalese, Polish and Slovak trekkers. Survivors said many victims perished trying to descend from the trail's highest pass in freezing, whiteout conditions.

The incident was the year's second major mountain disaster in Nepal, after an avalanche killed 16 guides on Mount Everest, the world's highest peak, in April.

This week's disaster was the worst since avalanches crashed down peaks in the Mount Everest region in 1995, killing 42 people, army officials said.

Nepal is home to eight of the world's 14 highest mountains. Income from tourism, including permit fees for trekkers, who made up more than 12 percent of its 800,000 tourists in 2013, accounts for four percent of its economy.

(Reporting by Rupam Jain Nair and Gopal Sharma; Editing by Douglas Busvine and Clarence Fernandez)