NEW : Teen killed when three bombs explode outside music festival . Four killed after suspected U.S. missile strike fired from drone , official says . Attack believed to be fourth in Pakistan since early November . The U.S.-led coalition and NATO , based in Afghanistan , have been seeking a way to effectively battle militants who are launching attacks from Pakistan 's swath of tribal areas along the border . Comment:
NEW : Teen killed when three bombs explode outside music festival . Four killed after suspected U.S. missile strike fired from drone , official says . Attack believed to be fourth in Pakistan since early November . Comment: