KABUL, Afghanistan — A suicide bomber killed 14 people on Tuesday including 10 foreigners, most of whom worked as flight crew members under contract with the United States government, officials said. The attack brought to at least 28 the number of deaths attributed to unrest sweeping the Muslim world as a result of an amateurish video parodying the Prophet Muhammad.


A spokesman for an Afghan insurgent group, Hezb-i-Islami, claimed responsibility for the bombing and said it was carried out by an 18-year-old woman.


“We claim credit for the attack by a martyrdom-seeking mujahid, an 18-year-old girl named Fatima, from Kabul, and the attack has been conducted in response to the film insulting the Prophet Muhammad and Islam,” said Zubir Siddiqi, the spokesman, reached by telephone.


The attack took place as word emerged that the American-led military coalition fighting the insurgents had sharply curtailed ground-level operations with the Afghan Army and police forces, potentially undercutting the training mission that is the heart of the Western exit strategy.


The new limits, which were issued Sunday and require a general’s approval for any joint work at the small-unit level, were prompted by a spike in attacks on international troops by Afghan soldiers and police over the past six weeks. There was also fear that anger over the anti-Islam video could prompt more of what the coalition calls insider attacks, American officials said.


The deaths in Kabul on Tuesday were the first here so far connected to the video, and came as the authorities cracked down on attempted street demonstrations and asked Internet providers to block sites hosting a clip of the film, posted under the name “Innocence of Muslims,” shutting down access to Google, YouTube and Gmail in the process.


Access to Google and Gmail appeared to have been restored on Monday afternoon, though officials said YouTube remained blocked for most Internet users. Google, which owns YouTube, refused a White House request to remove the video, saying it did not violate Google’s rules on hate speech. In Egypt, a radical cleric issued a fatwa calling for the killing of everyone involved in the video, according to a report posted on militants’ Web sites.


In the attack on Tuesday, the suicide bomber drove a car full of explosives head-on into a minibus carrying foreign workers on the Airport Road, killing all 12 people aboard and two people on the road, according to the police.


The United States Embassy here said in a statement that many of the foreign victims were personnel of a private company providing services to the United States Agency for International Development and other organizations in Afghanistan. American officials confirmed that at least eight had been employed by a South African aviation charter company, ACS/Balmoral, working under contract for USAID as pilots and crew flying planes in what is colloquially known as “Embassy Air” to provincial capitals in Afghanistan. A spokeswoman for ACS/Balmoral, Candice Teubes, said all eight were believed to be South African citizens.


The authorities in Afghanistan provided conflicting accounts. An aide to Gen. Mohammad Ayoub Salangi, the police chief of Kabul, said at least six of the 10 dead foreigners were South Africans, five men and a woman; one was a Filipino, and the others’ nationalities were uncertain.


Spokesmen for the French and Russian Embassies said they did not believe any of the victims were from their countries, contradicting earlier police accounts that the dead included French and Russian citizens.


The attack brought to at least 28 the number of people killed in six countries as a consequence of protests over the video since it came to public attention and was posted on YouTube in the days before Sept. 11. A Florida pastor, Terry Jones, whose small church had publicly staged burnings of the Koran last year, called attention to it in the United States, but it drew much wider attention in the Muslim world after an Arabic language version began to circulate on the Web.


The film was produced in the United States, though its origins are still shrouded. Muslims have depicted it as deeply insulting, but it is protected by American freedom of expression laws. American federal authorities identified the man behind the film as a convicted criminal named Nakoula Basseley Nakoula, 55, and took him in for questioning on Sept. 15 over possible federal parole violations. That action has so far done little to tamp down the rising unrest.