ISRAELI TANKS AND ARMORED PERSONNEL CARRIERS ENTERED NORTHERN GAZA LATE SATURDAY, PALESTINIAN RESIDENTS SAID, ACCORDING TO AP. THEY SAID THE ISRAELI FORCES CROSSED THE BORDER IN THE AREA OF THE TOWN OF BEIT HANOUN, IN THE NORTHEASTERN CORNER OF GAZA, OPPOSITE THE ISRAELI TOWN OF SDEROT, A FREQUENT TARGET OF PALESTINIAN ROCKETS. THE ISRAELI VEHICLES WERE POSITIONED IN PALESTINIAN FARMLAND OUTSIDE THE TOWN, THE RESIDENTS SAID. THE ISRAELI MILITARY DENIED THAT ANY ISRAELI FORCES WERE IN NORTHERN GAZA.