Tel Aviv - Israel withdrew its troops from the Gaza Strip Saturday after some of the fiercest gunbattles with Palestinian militants in the Hamas-run territory since last year's military offensive. Israeli troops used bulldozers to "remove infrastructure used by terrorists to attack soldiers" before the early morning withdrawal, a military spokeswoman said. Gaza militants, meanwhile, fired a rocket into southern Israel on Saturday, but no injuries were reported, the military said. Two others fell short of Israeli territory. The violence began Friday when soldiers patrolling the border crossed into Gaza after spotting Palestinians planting explosives near the fence with Israel. Two Israeli soldiers and two Palestinian militants were killed in the gunbattle, the military said. Palestinian medics said one civilian was killed and seven were wounded in the fighting. Militants reported one wounded and one missing. Israel's military held Gaza's Islamic militant Hamas rulers responsible for the violence. "We will not tolerate any attempt to harm the citizens of the state of Israel and we will continue to operate firmly against anyone who uses terror against it," a military statement said.