Israeli tank on the Gaza border Israel is ready to stop firing on the Gaza Strip if Palestinian militants in the coastal enclave end a barrage of rocket and mortar fire, Defence Minister Ehud Barak said on Sunday.

His comments came after Gaza's Hamas rulers declared a state of emergency for its security services in the wake of confrontations with Israel that have killed 18 Palestinians since Thursday. Barak said Israel was ready to end the confrontation, if Hamas and other armed groups stopped firing."If they cease firing, we'll cease firing," he said, reacting to reports that the Islamist movement's political wing is ready for a truce. We cannot tolerate firing" against Israel, said Barak, who has indefinitely postponed a trip to Washington in the face of escalating tit-for-tat violence around the territory where Israel fought a devastating 22-day conflict in December 2008-January 2009."We will act along the lines of what happens on the ground," he added.

It was the first time that an Israeli minister had floated the possibility of a ceasefire since deadly clashes with the Palestinians broke out on Thursday after an anti-tank missile fired from Gaza hit an Israeli school bus.Hamas and other armed groups in Gaza had previously announced a unilateral truce that unravelled before it had a chance to take hold, with militants firing dozens of rockets and mortar rounds into southern Israel.

But on Saturday, a senior Israeli security official said Hamas's political wing had asked Israel for a ceasefire."The political branch of Hamas has sent a message asking for an Israeli ceasefire" in exchange for a halt to Palestinian attacks, the official told AFP on condition of anonymity.He said military operations would continue for as long as Israel felt "its people cannot lead normal lives."Overnight, the situation calmed slightly but at least three mortar rounds were fired from Gaza into Israel early on Sunday, without causing casualties, the army said.

On Saturday, Hamas declared a state of emergency in the face of the deadly Israeli reprisals against the territory."The (Hamas) interior ministry has decreed a state of emergency. All security forces must work 24 hours a day along with the civil defence and medical services to protect and save inhabitants taken as targets by the Zionist occupier," ministry spokesman Ihab al-Ghussein said.

The confrontation between Israel and Hamas is the deadliest since the 2008-9 conflict. In retaliatory strikes, Israel has targeted several suspected top Hamas commanders, including Tayssir Abu Sneneh, a head of Hamas's armed wing, the Ezzedine al-Qassam Brigades.The Israeli army said Abu Sneneh was implicated "directly and physically" in the capture of conscript Gilad Shalit in a deadly cross border raid from Gaza in June 2006. He remains in captivity. Several rockets were fired at Ashkelon but were intercepted by the Iron Dome defence system. Abu Sneneh had also been charged with plans for "a terrorist attack from the Sinai Desert, using rockets, against the Israeli city of Eilat," the army charged.

Medics say at least 57 Palestinians have been wounded, 12 seriously, since the latest flare-up began on Thursday, when an anti-tank round was fired at an Israeli school bus near kibbutz Nahal Oz, close to Gaza.The attack critically wounded a teenager and injured the driver.Israeli reprisals have made the confrontation the deadliest since the end of Operation Cast Lead, the offensive Israel launched in December 2008 that claimed the lives of some 1,400 Palestinians -- more than half civilians -- and 13 Israelis, including 10 soldiers. Militant rocket fire from Gaza has been the first test of Israel's newly deployed Iron Dome short-range defence system, which the military said has successfully intercepted several industrially manufactured Grad rockets fired at the southern port of Ashkelon.The defence system, the first of its kind in the world and still experimental, is not yet able to provide complete protection, however, army commanders have warned.