Frustration is growing in parts of rural Nepal over the pace of relief efforts, with some badly-affected villages yet to receive any assistance.

Survivors in some areas told the (BBC) that they were angry that aid neither food nor medicine has reached them.

The UN has appealed for $415 million to help provide emergency relief over the next three months.

Officials say Saturday's quake killed more than 5,500 people, and injured at least 11,000.

The UN says more than eight million people have been affected by Saturday's 7.8-magnitude quake and some 70,000 houses have been destroyed.

The government says it has been overwhelmed by the disaster.

In several villages north-east of the capital, Kathmandu, no buildings have been left untouched and bodies are still lying under the rubble, according to the BBC.

Some helicopter crews who have managed to land in isolated communities have been faced with desperate villagers pleading to be airlifted to safety.

In Kathmandu, riot police clashed on Wednesday with protesters angry at a lack of transport out of the city and delays in distributing aid.

Thousands were waiting for buses to take them to rural areas.