A landslide crushed dozens of homes in a small Yemeni mountain village, killing at least 30 people with boulders the size of trucks and leaving scores missing, officials said Thursday.

Rescue workers heard moans and cries for help from under the ruins of the northern mountain village of Dhafeer after the overnight landslide, said Ahmad al-Maqdishi, a security official involved in the rescue effort.

The avalanche hit late Wednesday while most residents were still in bed, sending boulders the size of trucks crashing down, destroying about 30 homes.

Police said 30 bodies have been found so far and fear up to 100 could be missing.

Soldiers and civilians with shovels dug through the ruins of stone houses while a bulldozer pushed at larger stones.

"Big rocks came tumbling down the side of the mountain," said the village leader, Saleh Hamoud. "This is making it difficult to reach victims because they're stuck under these big boulders."

Hamoud said he escaped harm, but eight members of his family, including his wife and children, were missing.

The remoteness of the village — in the rugged mountains 60 miles north of the capital, San'a — and the inexperience of rescue workers was complicating the search operation, he said.

"We have little experience and limited capabilities. And what's making things worse is that it happened at night when everyone was asleep in their home," said Saleh.

Authorities said the area has been closed to people coming from neighboring villages trying to help because they were hindering the rescue.

Experts said the avalanche was not caused by an earhquake, rather by shifting of the mountain's boulders due to changes in temperature.

Ambulances rushed to the village, which takes its name from Dhafeer mountain, and major hospitals in the capital were put on emergency status.

For centuries, Yemenis have built their houses on the sides of mountains, sometimes carving homes out of the rockside.