KABUL, Afghanistan (AP) — A suicide bomber rammed a car packed with explosives into a mini-bus carrying foreign aviation workers to the airport in the Afghan capital early today, killing at least 12 people including eight South Africans. A militant group claimed the attack aimed to avenge an anti-Islam film that ridicules the Prophet Muhammad.

The powerful early morning blast was the first to target Kabul since a video clip of the film was posted on the Internet last week, sparking angry protests across the Muslim world including in Afghanistan. It was also the second — and deadliest — attack in Afghanistan that militants have said they carried out as revenge strikes in response to the film.

Haroon Zarghoon, a spokesman for the Islamist militant group Hizb-i-Islami, claimed responsibility for the dawn attack in telephone call to The Associated Press. He said it was carried out by a 22-year-old woman named Fatima. Suicide bombings carried out by women are extremely rare in Afghanistan — and few if any women drive cars.

“The anti-Islam film hurt our religious sentiments and we cannot tolerate it,” Zarghoon said. He said the 22-year-old Fatima volunteered to be the suicide bomber.

“There had been several young men who wanted to take revenge but Fatima also volunteered and we wanted to give a chance to a girl for the attack to tell the world we cannot ignore any anti-Islam attack.”

Zarghoon warned of more attacks against foreigners working for NATO and said the group had been seeking targets since a video clip of the film was posted on the Internet last week. The bombing was a worrisome escalation of violence in the capital, where most attacks are usually blamed on the Haqqani network — a Pakistan-based militant group affiliated with the Taliban and al-Qaida.

“Foreign troops are fighting against Afghans and foreign civilians are tasked to spy for them. They all are our enemy and will be our target,” Zarghoon told The AP, speaking from an unknown location.

Eight of the dead were South Africans believed to be working for an aviation company based at Rand Airport in Johannesburg, South Africa’s International Affairs Ministry spokesman Nelson

Kgwete said.

Afghan Interior Ministry spokesman Sediq Sediqqi said that four Afghans also were killed and another 11 Afghan civilians were wounded. He said tests were under way to determine whether the suicide bomber was a woman.

Today’s blast came a day after hundreds of Afghans burned cars and threw rocks at a U.S. military base in the capital in a demonstration against the anti- Islam film. One police vehicle was burned by the mob before they finally dispersed around midday Monday.

Kabul police chief Gen. Mohammad Ayub Salangi said today’s explosion took place near an avenue northwest of the city center near Kabul International Airport. The blast was so powerful it hurled the mini-bus at least 50 yards.

An eyewitness at the scene said he was waiting at a bus stop along the road when he saw a small white sedan ram into the mini-bus.

“The explosion was so powerful and loud that I could not hear anything for 10 minutes,” said Abdullah Shah, a teacher. “It was early and there wasn’t much traffic or there would have been many more casualties.”