OCCUPIED JERUSALEM, 21 June — Israel started mobilizing reserve soldiers yesterday and expanded its brutal military operations on the West Bank in the wake of two Palestinian bombings that killed 26 Israelis and left US peace efforts in limbo. The latest round of tit for tat violence forced US President George W. Bush to delay his much-anticipated announcement of a new Middle East strategy for fear his words would fall on deaf ears.

With scores of Israeli armored tanks and heavily armed troops in five West Bank towns and villages and helicopter gunships armed with missiles, the government vowed to occupy Palestinian land until the attacks stop. The helicopters also fired several missiles and destroyed some houses in Jabaliya refugee camp in the Gaza Strip town of Khan Yunis yesterday morning.

The Israeli Army last evening began an emergency call-up of reservists, Israeli public radio said. It did not say how many of the more than 400,000 reservists would be mobilized in the third call-up this year.

The news came as the Israeli military machine rolled yesterday into Bethlehem, Tulkarm and a suburb of Ramallah, the town where Palestinian President Yasser Arafat is currently headquartered. The army mounted its operations for a second straight day in the northern towns of Jenin and Qalqilya, where a pregnant woman was killed in fighting yesterday. It was also making deep incursions into Nablus, imposing a curfew on neighboring villages.

The local headquarters of the Democratic Front for the Liberation of Palestine was reported destroyed in Jenin. Israel also moved to protect the 150 Jewish settlements in the West Bank, declaring them “military zones” closed to all but Israeli citizens. The hawkish Israeli Prime Minister Ariel Sharon, frustrated by the inability of the region’s mightiest army to stem the attacks, vowed to punish any new bombings by seizing and holding on to Palestinian territory until they stop.

Palestinians killed four settlers on a Jewish settlement in the northern West Bank last night, where the fighters were still bunkered in a house holding hostages, public television reported. Before storming the house, the men had opened fire on the Itmar settlement grounds, near the city of Nablus, wounding five people, military radio said. An army unit had stormed a floor of the building where the Palestinians were holed up, the television said later, while gunmen fired on soldiers on the street.

Meanwhile, Arab information ministers yesterday launched a $22.5 million media campaign to denounce Israel’s “racist” policy and terrorism accusations in the West against the Arabs. The announcement came at the end of a two-day meeting at the Cairo headquarters of the 22-member Arab League. Part of the money will fund an “Arab media observatory” to be set up in Europe or the United States tasked with responding to accusations “portraying the Palestinian struggle as terrorism”.

The observatory will also seek to counteract charges of terrorism against Arabs, which have been frequent since the Sept. 11 terror attacks on the United States. Funds will also go to set up English- and Hebrew-speaking services on Arab public and private TVs to address international and Israeli public opinion, said Syrian Information Minister Adnan Omran, who chaired the meeting.