AFP/KabulA female suicide car bomber attacked a van in Kabul yesterday, killing 12 people, including eight South Africans, in an assault insurgents said was revenge for an anti-Islam film made in America.The bombing on a highway leading to Kabul international airport was the second suicide attack in the heavily fortified city in 10 days, reviving questions about stability as Nato accelerates a troop withdrawal and hands over 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 war strategy that focuses on training Afghans to take over.An AFP photographer saw at least six bodies lying among the wreckage of a gutted minivan, and another vehicle destroyed by flames still burning in the middle of the highway, with debris flung all around.“At around 6.45am (0215GMT) a suicide bomber using a sedan blew herself up along the airport road in District 15. As a result, nine workers of a foreign company and three Afghan civilians are dead, and two police are wounded,” 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 Afghan presidency later confirmed that three Afghans, believed to include the bus driver and an interpreter, and one citizen from Kyrgyzstan were also killed.Eleven other people were wounded, it said in a statement.Afghanistan’s second largest insurgent group, Hezb-i-Islami, claimed responsibility, saying it 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 insulting film,” spokesman Zubair Sidiqi said.It is extremely rare for the faction to claim a suicide attack in Afghanistan. It is also rare for women, few of whom drive in Afghanistan, to carry out suicide attacks. A police investigator said he believed the bomber was female, after finding parts of a woman’s leg.On Monday, protests turned violent for the first time in Afghanistan over the low-budget trailer for the film, which is believed to have been produced by extremist Christians, as hundreds hurled stones at a US military base and clashed with police.In the northern city of Kunduz, university students threw stones at police and set fire to photographs of US President Barack Obama in a fresh protest yesterday.