At least 876 people are known to have died in a powerful earthquake in Nepal, with many more feared trapped under rubble, officials say.

The 7.8 magnitude quake struck an area between the capital, Kathmandu, and the city of Pokhara, the US Geological Survey said.

Tremors were felt across the region, with further loss of life in India, Bangladesh and on Mount Everest.

The government has declared a state of emergency in the affected areas.

Nepali Information Minister Minendra Rijal said there had been "massive damage" at the epicentre, from where little information is emerging.

"We need support from the various international agencies which are more knowledgeable and equipped to handle the kind of emergency we face now," he said.

A national police spokesman told the BBC that 876 people had died in the quake.

Rescuers are digging through the rubble of collapsed buildings in the capital trying to reach survivors.

A number of historic buildings have been destroyed.

Among those wrecked was the landmark Dharahara tower, with many feared trapped in its ruins.

After the earthquake struck, frightened residents came out into the streets. Mobile phones and other communications have been disrupted.

(BBC)