"Local volunteers and police personnel are digging through six-feet (deep) snow with shovels looking for more bodies," said Gautam Rimal, assistant chief district officer in the area where Langtang is located.
The dead include at least seven foreigners but only two had been identified, he said.
It was not clear how many people were in Langtang at the time of the avalanche but other officials said about 120 more people could be buried under the snow.
"We had not been able to reach the area earlier because of rains and cloudy weather," Uddhav Bhattarai, the district's senior bureaucrat, said by telephone on Sunday.
The April 25 earthquake has killed 7,366 people and wounded nearly 14,500, Nepal's government said. The disaster has prompted an international relief and rescue effort.
Read MoreHow to donate to Nepal earthquake relief
A European Union source on Monday revised sharply downwards to about 60 the number of citizens from the 28-nation bloc still unaccounted for. Last week a senior EU source had estimated around 1,000 EU citizens were missing after the quake.
The number is "going down by the hour" as rescue teams reach remoter areas, the EU source said.
The chief of India's National Disaster Response Force (NDRF), which was among the first foreign organisations to arrive after the quake, said it had been asked by the Nepalese government to conclude its search and rescue operation.
"All the search and rescue teams, not the relief (teams) ... have been asked to return," NDRF Director General O.P. Singh told Indian television. "We will see how best it can be done."
Everest still open to climbers
At least 18 of the trekker deaths were on Mount Everest, where avalanches hit the slopes of the world's highest peak. The government said on Monday that it had not closed the mountain to climbers, though the route up to the peak was damaged.