BBC news with Marion Marshal

The commander of American forces in Afghanistan General John Allen says he's very angry about the sharp rise in attacks on his troops by their Afghan colleagues. He made his comments in an interview for the CBS 60 Minutes program.

"I'm mad as hell about them, to be honest with you. We're going to go after this. It reverberates everywhere across the United States. We're willing to sacrifice a lot for this campaign, but we're not willing to be murdered for it."

However, General Allen went on to insist that most Afghans supported the western military presence in their country.

General Allen was speaking as international forces in Afghistan investigated the death of another American serviceman. Two thousand US troops have now died since fighting began 11 years ago. A US civilian contractor and three Afghan soldiers were also killed in the incident in Wardak province. The shooting was initially blamed on a rogue Afghan soldier. But an ISAP spokesman Lieutenant General Adrian Bradshaw said that may be wrong.

"What was initially reported to have been a suspected insider attack is now understood possibly to have involved insurgent fire."

An angry crowd has turned on Somalis living in the Kenyan capital Nairobi after a grenade thrown into a Christian Sunday school killed one child and critically wounded several others. Gabriel Gatehouse is in Nairobi.

Retaliation was swift. No group or individual has admitted carrying out the attack. But as Kenyan troops battle Islamist militants in Somalia, this church bombing is blamed almost immediately on al-Shabab. Angers built over into violence as dozens of men attacked a nearby mosque. Police said 13 people were wounded but that order has been restored. The church is near a suburb of Nairobi called Eastleigh, also known as little Mogadishu where the majority of residents are Somali origin.