Israeli troops killed four armed members of the security force led by the governing Palestinian Hamas movement Monday, amid a series of clashes in Gaza and the West Bank, hospital officials and witnesses were quoted by dpa as saying. A 15-year-old Palestinian teen was also killed when an apparent projectile left behind by Israeli troops exploded in northern Gaza, witnesses said. Palestinian hospital officials said a sixth Palestinian was shot dead by Israeli troops in the southern Gaza Strip, while another militant was killed in a raid on the West Bank city of Ramallah Monday evening.