Pakistan has protested to US-led coalition forces in Afghanistan after eight Pakistanis were killed in alleged cross-border firing on Saturday. \"We have protested to the coalition forces because they are responsible for security on the other side,\" Foreign Ministry spokeswoman Tasnim Aslam said. She said US forces had not entered Pakistani territory. The US military says it is looking into the incident. Residents in Waziristan say helicopters attacked a house during the night. \"Helicopters bombarded the house late on Friday night, leaving eight people dead,\" Salimullah, a tribal elder in the village of Saidgai, 12 km (eight miles) north of Miran Shah, told the AFP news agency. He also said a number of people were injured. Pakistan\'s army has been battling Islamic militants in the Waziristan region for the last three years. Taleban and al-Qaeda fighters fled into the area after the American-led invasion of Afghanistan in 2001. Tens of thousands of Pakistani soldiers are deployed in the area. Across the border, about 20,000 US-led coalition forces are hunting Taleban, al-Qaeda and other militants opposed to the US-backed government of President Hamid Karzai. There have been a number of reports, and denials, that US troops have crossed over the rugged, poorly-demarcated border separating Afghanistan and Pakistan. (BBC)