An earthquake, 7.4 in magnitude and only 19km deep, has hit 68km west of Namche Bazar, Nepal, according to US Geological Survey.

It comes just a few weeks after a devastating 7.8-magnitude quake left over 8,000 people killed, and almost 18,000 injured.

Around 8 million people in Nepal, which has a total population of 28 million, have been affected by the disaster, the UN estimated.

Some 2 million people still need tents, drinking water, food and medicine.