Israeli tanks forged into the southern Gaza Strip yesterday, drawing mortar fire from Palestinian militants and intensifying violence that has chipped away at a tenuous cease-fire.

Israel and Hamas have been trading fire for two weeks after nearly five months of relative quiet. The June 19 truce is due to expire next month, and both sides might be trying to dictate more favorable terms in anticipation of the agreement's renewal.

The tanks, backed by a bulldozer and military jeep, rumbled about half a km deep into the tiny seaside strip, residents and Gaza security officials said. Residents said they leveled lands along the border east of the city of Rafah. It was the first ground action in a week.