The number of people killed in a devastating snowstorm in Nepal's Himalayas climbed to 43 on Saturday, in the worst trekking disaster ever to hit the mountainous country.

More than 230 trekkers - most of them foreigners - have been rescued since Wednesday and search teams continue to scour the Annapurna range looking for more survivors, who may be sheltering in lodges and huts.

Officials believe some people may be stranded in waist-deep snow in remote locations where mobile phone signal is poor.

The skies were clear at the start of the week, said Gombu Sherpa, who was guiding a group of Germans near the popular trekking circuit. But that changed suddenly when the snow blew in.

"We could hardly see anyone, even within a couple of feet. The wind was blowing snow and visibility was almost zero," he said, adding many people lost their way in the storm, but that everyone in his group survived.

One of his assistants, who was behind the group when the storm hit, was missing for an entire night, lost in the blizzard.

"We found him the next morning wandering in the snow. It is a miracle that he is alive," he said. Two trekkers from Hong Kong and 12 Israelis survived by taking refuge in a small tea shop.

One of the Israelis, Yakov Megreli, said they tried to stay awake to stay warm. "We tried not to sleep. We tried not to get hypothermia. It was a very frightening and awful situation," he said.

A British survivor has told how he escaped the disaster.

Paul Sheridan said walkers were left stumbling through "an abyss of nothing" as dense snow left them unable to get their bearings on the slopes of the mountain range in northern Nepal.

Mr Sheridan said that trekkers should have been prevented from going up the mountain, but were "herded to their deaths" by guides who he alleged were not carrying the correct emergency equipment.

Friends of Briton Lizi Hamer, who was originally unaccounted for, posted a message on Facebook announcing she had been found safe.

The 240km Annapurna circuit offers spectacular views of jagged peaks and Buddhist villages.

It takes almost three weeks to complete and is nicknamed the "apple pie" circuit because of the teahouses lining the route that offer cold beer and home baking.