Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Suicide Bomber Kills 8 Americans in Afghanistan VOA News 30 December 2009 Afghanistan Map Afghanistan Map U.S. officials in Kabul says a suicide bomber in eastern Afghanistan has killed eight Americans. Officials have released few details about the blast in Khost province, including whether the victims were American soldiers or civilians. Khost province borders Pakistan's North Waziristan tribal region, where Taliban militants and their allies launch cross-border attacks. Meanwhile, a spokesman for international troops in Afghanistan says NATO so far has no direct evidence to back up Afghan government claims that foreign troops killed 10 civilians in eastern Afghanistan on Sunday. Colonel Wayne Shanks told reporters Wednesday that NATO has requested an immediate joint investigation into the incident. Afghan government investigators earlier concluded that foreign troops killed 10 civilians - including school children - during Sunday's operation in Kunar province. An advisor to Afghan President Hamid Karzai, Asadullah Wafa, says his team spoke with villagers and officials in Kunar province's Narang district and determined the dead included eight teenagers. The victims were buried before the Afghan team arrived. Wafa said officials are now trying to find the informant who provided information that led to the attack. Hundreds of university students took to the streets in Kabul and in the eastern city of Jalalabad Wednesday to protest the killings. Many expressed anger toward the United States and U.S. President Barack Obama, some chanting "Death to Obama." Some held large photos of children they said were killed by foreign troops. The United Nations released figures Tuesday indicating civilian deaths in Afghanistan rose more than 10 percent in the first 10 months of this year compared to the same period in 2008. The top U.S. and NATO commander in Afghanistan, General Stanley McChrystal, has made protecting civilians a top priority for foreign troops in Afghanistan. On Wednesday, Bulgaria said it plans to send another 30 troops to Afghanistan, boosting the total number of Bulgarian troops there to 300. The Bulgarian troops are providing security for the inner zone of the Kandahar airport. Some information for this report was provided by AFP, AP and Reuters. .