KABUL, Sept 18: A woman suicide bomber attacked a van in Kabul on Tuesday, killing 12 people, including eight South Africans, in an assault militants said was revenge for an anti-Islam film made in America.

The bombing on a highway to Kabul airport was the second suicide attack in the city in 10 days, reviving questions about stability as Nato accelerates a troop withdrawal and hands over responsibilities to Afghan forces by the end of 2014.

It came as officers revealed that western troops are scaling back joint operations with Afghans after 51 Nato soldiers were shot dead this year by their local colleagues, a setback for the strategy that focuses on training Afghans.

At about 6.45am a suicide bomber and a sedan blew up along the airport road in District 15. “As a result, nine workers of a foreign company and three Afghan civilians are dead,” police said in a statement.

The South African foreign ministry said eight of its citizens working for a private company at the airport were among the dead.

The US embassy later confirmed that many of the dead worked for a private company providing services to USAID, as well as other organisations, and sent its condolences to the families.

Afghanistan’s second largest militant group, Hezb-i-Islami, claimed responsibility, saying the bombing was carried out by a woman to avenge the ‘Innocence of Muslims’ film, which has sparked a week of furious anti-US riots across Asia, North Africa and the Middle East.

“The bombing was in retaliation for the insult to our Prophet,” spokesman Zubair Siddiqi said in a telephone call from an undisclosed location.

It is extremely rare for the faction to claim a suicide attack. It is also rare for women, few of whom drive in Afghanistan, to carry out suicide bombings.

A police investigator said he believed the bomber was female, after finding parts of a woman’s leg. Meanwhile, under new orders, most joint patrols and advisory work with Afghan troops — the cornerstone of Nato departure plans — will have to be approved by a regional commander.

Cooperation with smaller units will have to be “evaluated on a case-by-case basis and approved by RC (regional) commanders”, Isaf said in a statement.

Nato, which is helping the Afghan government fight a Taliban-led armed campaign now in its 11th year, is gradually withdrawing its 112,600 remaining troops and US commanders have struggled to stem the problem of insider attacks.

The commander of US and Nato troops in Afghanistan, Gen John Allen, “has directed all operational commanders to review force protection and tactical activities in the light of the current circumstances”, a US military officer in Washington said in an email.

Defence Secretary Leon Panetta, speaking at a news conference in Beijing, said the attacks were worrisome but insisted they would not delay or derail plans to complete a withdrawal of troops by the end of 2014 as planned.

The decision came after six Isaf soldiers were shot dead by suspected Afghan policemen and after the Taliban destroyed six US fighter jets in an unprecedented assault on a major base in the south this weekend. —AFP