GAZA - Several Israeli tanks entered the northern Gaza Strip on Saturday in a raid the army said was aimed at stopping Palestinian militants from firing makeshift rockets at the Jewish state. Palestinian witnesses said tanks had moved on to farmland near the town of Beit Hanoun. There were no clashes.The Israeli army said the troops were still in the area several hours after they had entered in the early hours of Saturday, and their operation was continuing. “We are trying to stop cells from going into these areas and carrying out rocket attacks,” an army spokesman said. He added later that militants fired one rocket into southern Israel after the tanks entered.