Police have detained a dozen students for an anti-American protest. They rallied at the U.S. Embassy in central Seoul to demand an official apology for the deaths of two teenage students. The students shouted slogans that called on U.S. President George W. Bush to apologize for what they called "murder" of the two girls. The 14-year-olds were killed last month after being run over by a U.S. armored vehicle on a training mission in Euijungbu north of Seoul. Earlier Friday, several unidentified men threw firebombs over the wall of Camp Red Cloud in the city in apparent protest against the incident. No property damage was reported. A spokesman of the U.S. military command in Seoul said it was disappointed by that kind of violent demonstrations. The South Korean government expressed regret and promised to investigate the incident. Two U.S. soldiers whose armored vehicle killed the two girls were arraigned on Tuesday at a U.S. military court on charges of negligent homicide.