The United Nation says one of its cargo helicopters has crashed in South Sudan, with unconfirmed reports saying it was shot down.

A search and rescue team has been sent to the crash site near Bentiu, said the UN mission in South Sudan.

A UN official told the AP news agency the Mi-8 helicopter had apparently been shot down.

Thousands of people have been killed this year in bitter fighting between South Sudan’s army and rebel forces.

Bentiu, capital of the oil-rich Unity state, has changed hands several times but a ceasefire agreement is currently in place.

On Monday, the two sides were given 45 days to form a power-sharing government.

The AFP news agency says the Mi-8 would normally have between three and five crew on board.