JERUSALEM - Interim Israeli Prime Minister Ehud Olmert accused the Islamist Hamas movement yesterday of "shattering" the Gaza truce, after two rockets hit Israel, prompting an air strike which killed four Palestinian militants.

Olmert told the weekly cabinet meeting that Israel could not stand idly by while it came under repeated rocket fire and said he had ordered security chiefs to draw up action plans against Hamas's 17-month-old rule in Gaza.

His comments came as defense officials said that Israel's border crossings would remain closed to humanitarian deliveries to territory despite mounting international pressure.

"The responsibility for the shattering of the calm and the creation of a situation of prolonged and repeated violence in the south of the country is entirely on Hamas and the other terror groups in Gaza," Olmert told ministers. "We cannot tolerate this price tag that the terror organizations are trying to set against our right to prevent the continuing terror attacks and threats," he said.

Olmert said that he had asked security chiefs to draw up options for action against Hamas rule. "I instructed them to... present different action plans against the Hamas terror rule without its hampering our ability to use all necessary force in our response to violations of the calm."

’Media manipulation’
Hamas roundly rejected the Israeli premier's comments, dismissing them as "media manipulation" which had "no basis in reality". "It is our right to respond firmly to any Zionist aggression against Palestinians," Hamas spokesman Fawzi Barhum said.

Israeli FMTzipi Livni echoed the prime minister's remarks, a senior official said. "The calm is being violated, that's a fact. Israel can't accept violations without taking the action it determined ahead of time," she was quoted as saying. "The army must present the options."

Earlier yesterday, two rockets hit Israel without causing any casualties or damage, prompting a retaliatory air raid against Gaza City, which killed four militants. An Egyptian-brokered truce between Israel and Hamas came into force on June 19 and despite sporadic violations by both sides had led to a prolonged calm on the border until a fresh flare-up on Nov. 5.

Also yesterday, Israel maintained the crippling blockade, which has forced the United Nations to suspend food distribution to 750,000 Gaza residents and the territory's sole power plant to shut down.

"The crossings will remain closed until further orders," said Israel's liaison officer for the Palestinian territories, Peter Lerner.