NAIROBI • At least 50 African Union soldiers are believed to have been killed and another 50 are missing after Al-Qaeda-linked Shebab militants overran a military camp in southern Somalia, according to Western military officials.

Tuesday's attack on the camp in Janale, 80km south-west of Mogadishu, is one of the deadliest yet against the troops.

A briefing note sent to diplomats by Western military officials yesterday said that, in total, around 100 soldiers were "unaccounted for" after the attack.

Shebab, Somalia's Al-Qaeda affiliate, said the attack was revenge for the July killing of seven civilians by Ugandan troops at a wedding in the town of Merka. The group recently lost a string of key bases in the face of an offensive by the African Union Mission to Somalia (Amisom).

Western military sources said the attack began with the destruction of two bridges, cutting the camp off.

A suicide car bomber rammed the base, followed by an estimated 200 Shebab fighters who overran the camp.

Amisom said its troops "undertook a tactical withdrawal" as the attack began, and the briefing note said the soldiers did not have any air support. "Low cloud and landing restrictions prevented air support by UN-contracted support helicopters," it said.

It also said Kenyan and Ethiopian jets, as well as US drones, "were unavailable at the time of the attack" while Amisom tanks and artillery located in Janale had been redeployed elsewhere.

The report highlights the challenge that Amisom faces in holding territory seized from the Islamists, who frequently melt away into the bush in the face of conventional offensives and subsequently strike back with guerilla assaults.

The Shebab is fighting to overthrow the internationally backed government in Mogadishu, which is protected by Amisom.

AGENCE FRANCE-PRESSE