Israeli warplanes attacked several sites in the Hamas-ruled Gaza Strip Sunday, sources on both sides said, hours after a rocket from the Palestinian enclave hit the Jewish state. Palestinian medical and security sources said five sites in **rthern and southern Gaza were hit, including training camps for the militant Islamic Jihad and Ezzedine al-Qassam Brigades, Hamas's military wing. The Israeli army said in a statement it "retaliated" to "ongoing rocket attacks from Gaza", targeting four "terror sites" in **rthern Gaza and a fifth in the south of the coastal territory. On Saturday night, a rocket fired from Gaza hit an open area in southern Israel without causing damage or injuries, the army and police said.