A suicide bomber has killed at least 12 people in an attack on a mini-bus carrying foreigners near the Afghan capital.

Police say nine foreign workers, their Afghan driver, and two other Afghans were killed when the bomber detonated a car full of explosives near the bus Tuesday on the highway to the Kabul airport. South Africa’s Foreign Ministry confirmed eight of the dead were South Africans.

Afghan insurgent group Hezb-e-Islami claimed responsibility for the attack, saying it sent a female bomber in response to an anti-Islam, online video that has sparked worldwide protests, including in Afghanistan.

Meanwhile, NATO confirmed it is scaling back joint operations with Afghan security forces amid a series of recent insider attacks and the release of the video.

Fifty-one international troops have been killed this year in at least 30 insider attacks.

Coalition spokesman Charlie Stadtlander said in a statement, “most partnering and advising will now be at the battalion level and above. The need for partnering below that level “will be evaluated on a case by case basis by RC [regional] commanders.”

Stadtlander said the head of U.S. and NATO forces in Afghanistan, General John Allen, directed all operational commanders to review force protection and tactical activities “in light of the current circumstances.” The guidance was given at the recommendation of, and in conjunction with, key Afghan leaders.

Britain’s Foreign Secretary William Hague played down the measure in comments to British lawmakers on Tuesday, saying the impact on British operations “will be minimal.” In a statement issued later on Tuesday, NATO reaffirmed that it remains “committed to partnering with, training, advising and assisting Afghan forces.”

In Beijing, U.S. Defense Secretary Leon Panetta told reporters the insider attacks were a matter of concern but that General Allen is taking the necessary steps to counter the problem. Panetta added that NATO’s plan to handover security responsibility to Afghan forces by the end of 2014 remained on track.

NATO separately issued a statement recognizing Kabul police’s “proactive role” in maintaining control of recent demonstrations and its efforts to “maintain public calm.” NATO reiterated its condemnation of the “inappropriate videos that were disrespectful” toward Islam and “contrary to the thoughts and values of the coalition.”

Also Monday, NATO said it has sent a team to investigate a coalition operation that resulted in “several Afghan civilian casualties” in eastern Afghanistan.

Afghan officials said a coalition airstrike Sunday killed eight women as they gathered firewood in Laghman province.

NATO said it targeted a large group of armed individuals showing hostile intent. It says the airstrike killed several insurgents and also resulted in the “unintentional deaths of a number of Afghan civilians.”

NATO says it takes civilian casualties seriously and will conduct a complete assessment of the incident. The coalition offered its “sincerest regret” to the families of those killed.

This week’s violence comes just days after insurgents dressed in U.S. Army uniforms attacked a British military base in the southern province of Helmand. The militants, armed with automatic rifles, rocket propelled grenade launchers and suicide vests killed two U.S. Marines and destroyed jets and refueling stations during Friday’s assault in Camp Bastion.

Tuesday, NATO said an Afghan and coalition force arrested one of the Taliban leaders behind the Camp Bastion attack during an operation in the Nad Ali district of Helmand province.