OCCUPIED JERUSALEM, 18 March — Fresh killings and an incursion by Israeli tanks back into the West Bank town of Bethlehem broke a two-day lull in violence yesterday and jolted a US bid to broker a cease-fire. US envoy Anthony Zinni had already hit a wall of mistrust when his efforts were further complicated by a Palestinian gunman’s shooting spree in central Israel, a bombing in east Jerusalem and clashes in Bethlehem.

But Zinni vowed to press ahead with a cease-fire mission clouded yesterday by the shooting in Israel, bombing in Jerusalem and fighting in Bethlehem. Hours after the violence erupted, Zinni began talks with Palestinian President Yasser Arafat in Ramallah.

The Israeli Army slapped a curfew on a Palestinian self-rule area in the southern Gaza Strip last night, Palestinian witnesses said. Israeli soldiers ordered Palestinian residents to stay in their homes in the city of Khan Yunis’ Al-Matahen neighborhood, which is near the sprawling Jewish settlement bloc of Gush Katif. “Israeli soldiers in military jeeps, flanked by tanks ... told residents by loudspeakers not to leave their homes and announced a curfew till Monday morning,” a witness said.

Three Palestinians and one Israeli woman were killed in the latest spurt of bloodshed, which erupted as Zinni was going into talks with Arafat, on the fourth day of his closely watched attempt to end nearly 18 months of violence. A Palestinian man also died yesterday in a mysterious blast just outside Jerusalem. The incidents were likely to harden the Jewish state’s demands for guarantees against future attacks and the Palestinians’ insistence that Israel withdraw completely from all territory ceded to self-rule.

Israeli tanks rolled back into the center of Bethlehem where clashes between Israeli soldiers and armed Palestinians erupted, an AFP correspondent reported. Palestinian security sources said a 22-year-old member of the Al-Aqsa Martyrs Brigades, an armed offshoot of Arafat’s Fatah group, was killed during the Israeli Army incursion. They said five tanks rolled into the heart of Bethlehem, six moved into the nearby village of Beit Jala and four more into Ad-Doha, a village facing the refugee camp of Deheishe.

Zinni arrived Thursday on his third peace mission for US President George W. Bush in the territories. The retired US Marine Corps general looked on the verge of a breakthrough late Saturday after Sharon’s office said the Israeli leader was ready to attend three-way cease-fire discussions yesterday. But the office retracted its statement less than an hour later after the Palestinians demanded Israel withdraw from what is known as Area A, territory ceded to full Palestinian security and administrative control.