About 30 IDF tanks and bulldozers moved into the southern Gaza Strip on Tuesday in an operation against Palestinian gunmen, the military said, setting off clashes with Hamas operatives firing rocket-propelled grenades and mortar shells. Soldiers took over the rooftops of several homes and arrested about 60 people in house-to-house arrest raids, residents said. The gunfire kept frightened motorists away from the main road between the towns of Khan Yunis and Rafah, which was blocked at one section by an IDF tank. Troops also were demolishing a gas station on the road. The military described the operation as a routine operation "against the terror infrastructure."