BBC News with Marion Marshall

At least 75 people have been killed in South Sudan in an attack on a town in oil-rich Unity state. It's the worst such violence since independence in July. An army spokesman told the BBC that 15 civilians were among the dead after rebels from the South Sudan Liberation Army, the SSLA, attacked the town of Mayom. With more details, here's James Copnall in Khartoum.

The SSLA attacked Mayom in the early hours of Saturday morning. They say they have taken control of the town. But the army spokesman, the commissioner of the region and a local resident told the BBC the rebels' assault had been repulsed. Although some rebel movements have struck deals with the government since South Sudan became independent, several remain defiant. They say they are fighting against corruption, underdevelopment and the domination of the Sudan People's Liberation Movement - the former rebels who now run South Sudan. The SSLA's rebellion is particularly sensitive because of its location. Most of South Sudan's oil fields are in Unity state, and oil accounts for 98% of the new country's revenue.

Fighters from the al-Shabab group in Somalia have staged a concerted attack on a base used by troops from the African Union. The attack began when two suicide bombers approached the base on foot in the capital Mogadishu and detonated their explosives.

A suicide car bombing has killed 13 Americans serving with the international force in Afghanistan. The bomber targeted a bus carrying troops on the outskirts of Kabul. The Taliban said they carried out the attack. Quentin Sommerville in Kabul has more.