Updated | Hundreds dead in powerful Nepal earthquake

At least 876 people were killed as a powerful earthquake, with a 7.9 magnitude hit central Nepal, between the capital of Kathmandu and the city of Pokhara. Many more are feared trapped under rubble, officials say.

It is the worst earthquake to strike Nepal since one in 1934 all but destroyed Kathmandu, and the Nepali government has declared a state of emergency in the affected areas.

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

Earthquake tremors were felt across the region, with deaths also being reported in India, Bangladesh, Tibet and on Mount Everest.

World heritage sites in Kathmandu have been destroyed, including the UNESCO World Heritage temples at Basantapur Durbar Square and the Dharahara tower.

Eyewitness pictures posted on Twitter show that some of these monuments have been reduced to rubble, while others have severe cracks and are in risk of collapsing.

250 people were reportedly inside in the Dharahara tower when it collapsed, and a further 50 people are believed to be trapped under an ancient tower in Kathmandu that also collapsed in the quake.

Kathmandu’s airport has also reportedly suffered damage, which could hamper relief operations.

Residents and bystanders helped emergency workers, army and police personnel early Saturday afternoon to clear the rubble from these sites and to rescue any survivors from underneath the debris.

Thousands of people have sought refuge in Kathmandu’s open spaces, fearing that subsequent earthquake aftershocks could cause further damage.

The quake triggered an avalanche on Mount Everest, killing at least eight people, and another five in Tibet, officials and reports say.

The Associated Press news agency reported that the quake had triggered an avalanche on Mount Everest, killing at least eight people and a further five in Tibet.

Indian Prime Minister Narendra Modi has held a Cabinet meeting to review the situation, while Pakistani Prime Minister Nawaz Sharif has pledged to help the Nepalese authorities.