Palestinian militants set off a bomb next to an Israeli tank in a convoy travelling through the Gaza Strip yesterday, killing three Israelis just hours before the start of a peace mission by the United States special envoy Anthony Zinni. A statement sent to the Reuters news agency said the attack was a joint operation by the al-Aqsa Martyrs Brigades, an armed group linked to President Yasser Arafat's Fatah movement, and the Salahudin Brigade, which unites militants mainly from Fatah and the Islamic movement Hamas. With Israelis and Palestinians predicting Mr Zinni's latest mission is doomed, the attack on the convoy of soldiers and Jewish settlers will complicate his attempts to secure a ceasefire. The prospects for negotiations have already been undermined by a sweeping Israeli military offensive inside Palestinian territory. Dore Gold, an adviser to Israel's Prime Minister, Ariel Sharon, said he doubted the Palestinians wanted to end the violence. "So we go into this with a willingness to try, with a willingness to go the extra mile, but with a large degree of scepticism about Arafat's intentions," he said. A Palestinian political analyst, Ghassan Khatib, also doubted that Mr Zinni, a retired general, could negotiate a lasting truce. He said the only way to end the bloodshed was to deal with the core issue of the conflict - Israel's occupation of the West Bank, Gaza Strip and east Jerusalem, which it seized during the 1967 Middle East war. Mr Zinni is expected to put the idea of US monitors on the table, a move Mr Khatib described as positive. Israel has opposed international observers in the past, but Mr Gold said a small number of US monitors might be acceptable. "Should the Central Intelligence Agency become active in monitoring the ceasefire that I am sure General Zinni will try and create, having some people on the ground looking at what is going on and giving an objective report may not be a bad idea," he said. Ahead of Mr Zinni's visit, Israeli tanks pushed into two towns in the West Bank, despite strong criticism from the US, the United Nations and the European Union that the military campaign was harming the chances for peace talks. President George Bush said: "Frankly it's not helpful what the Israelis have done, in order to create the conditions for peace. I understand someone trying to defend themselves and to fight terror, but the recent actions aren't helpful." Also in Washington, White House and congressional sources said the Bush Administration was blocking a request from Israel for hundreds of millions of dollars in new aid. But despite such pressure and protests from his own Defence Minister, Binyamin Ben-Eliezer, Mr Sharon insisted the Israeli Army's operations would continue, even during Mr Zinni's visit. The Israeli Army's siege of Ramallah continued yesterday. Its soldiers shot dead three Palestinian gunmen during intense street fighting. On Wednesday several dozen Israeli tanks and armoured vehicles had been seen pulling out from Ramallah's city centre and leaving through its southern entrance, but Israeli military sources discouraged talk of a withdrawal and said the movement might be tactical. Israeli troops also held firm to positions in the West Bank towns of Qalqilya and Bethlehem. In Bethlehem, Palestinian militiamen shot dead two suspected informers for Israel, and tried to hang the body of one of them from a building on Manger Square. Source: Sydney Morning Herald