Suicide bombing in Kabul kills foreigners 18 (UPI) -- A suicide car bomber in Afghanistan attacked a bus carrying foreigners in Kabul early Tuesday, killing up to 12 people, authorities said. The attack follows a weekend of deadly violence that included the deaths of eight coalition troops in so-called insider attacks and a daring insurgent assault on Camp Bastion. The attacks also come as protests against the United States over an anti-Islam film spread across the Muslim world. The BBC reported the attacker in the Tuesday bombing, identified as a young woman, set off the explosion as the bus traveled on a major highway leading to the international airport in the Afghan capital. It quoted officials as saying up to 12 people had died, most of them foreigners. The bus was believed to be carrying the airport's international staff. CNN, quoting an Afghan official, said the bus was attacked on the main road leading to the Afghan capital's international airport. Those aboard the bus included foreigners and an Afghan interpreter, the report said. CNN said at least 10 others were wounded in the attack. The report said video footage showed military officials around the smoldering vehicle. China's Xinhua news agency quoted a police official as saying, "A suicide bomber targeted a minibus carrying foreign nationals along a main road from Kabul airport to Kabul intercontinental hotel, leaving at least nine foreigners dead." Xinhua said the explosion occurred at around 6:45 a.m. local time. Xinhua quoted a local television channel TV channel also saying nine foreigners died in the attack. A senior counter-terrorism official in Kabul told the BBC: "We can confirm that the suicide attack was carried out by a female suicide attacker. She is either a young girl or a woman. The nationalities of the foreigners are not yet known. Joint military operations between the United States and Afghanistan were indefinitely suspended Monday after the weekend insider attacks in which those killed included four Americans. "We're to the point now where we can't trust these people," a senior military official told NBC News. It's had a major impact on our ability to conduct combat operations with them, and we're going to have to back off to a certain degree. Among the troops killed in the insider attacks, six, including four Americans, died Sunday at a remote checkpoint near a NATO installation in southern Zabul province. In a similar insider attack on Saturday, two British soldiers were killed in southern Helmand province by an Afghan believed to a member of the local police. Separately last Friday, the Taliban launched a daring attack on the heavily fortified Camp Bastion base in Helmand province, killing two Marines and damaging or destroying eight attack jets with damage estimated at more than $200 million. One insurgent was captured and 14 others were during the subsequent fighting. The Taliban have stepped up their violence as U.S. forces plan to end combat operations in Afghanistan by 2014, allowing Afghan forces to take control of their country. Afghanistan has been relatively quiet so far even as the protests over the anti-Islam film.