Pakistan has lodged a strong protest with U.S.-led forces in Afghanistan after cross-border firing over the weekend killed eight people. U.S. authorities had denied their troops were involved in the firing on Saturday in the restive, semi-autonomous North Waziristan tribal region, Foreign Ministry spokeswoman Tasnim Aslam told a regular briefing on Monday. Although Pakistan did not know who was behind the firing, U.S.-led forces were responsible for the area, she was quoted as saying by the Associated Press. "We have also lodged a strong protest with coalition forces in Afghanistan," she said. "We have protested to coalition forces because they are responsible for security on the other side," she said.