Two United Nations peacekeepers from India were killed and a third wounded when a UN base in South Sudan was overrun by armed youths yesterday evening, UN spokesman Joe Contreras confirmed this morning.

Previous reports had indicated three Indian peacekeepers died.

Mr Contreras said two civilians were also killed when Lou Nuer youths breached a UN compound in Bor, in Jonglei State.

He could not confirm comments by presidential spokesman Ateny Wek Ateny that 54 people from the ethnic Dinka group were killed in the raid.

US President Barack Obama yesterday urged clashing factions in South Sudan to end violence, restore calm and work towards reconciliation.

He said the conflict threatens to derail progress the country has made since gaining independence.

"Inflammatory rhetoric and targeted violence must cease," Mr Obama said in a statement.

"All sides must listen to the wise counsel of their neighbours, commit to dialogue and take immediate steps to urge calm and support reconciliation."