OCCUPIED JERUSALEM, 10 December — The spiral downward continues in occupied Jerusalem. Five more Palestinians were assassinated yesterday and a Palestinian activist wounded at least 22 people near Haifa when he tried to blow himself up. An earlier report put the number of Israelis injured at 26. Most of the wounded suffered only slight injuries and many others were treated for shock and post-explosion anxiety. The Palestinian man was shot dead by Israeli troops.

Prime Minister Ariel Sharon warned Israel might step up military strikes in the West Bank and Gaza Strip.

Hamas, Islamic Jihad and two other groups, meanwhile, said in a statement yesterday they would halt attacks within Israel for a week if the Israeli military stopped its strikes in the West Bank and Gaza Strip.

A senior Israeli security official dismissed the offer and said Israel had no choice but to continue to “act in self-defense” as long as the Palestinian Authority failed to “fight terrorism and make arrests”.

Early yesterday, Israeli troops backed by tanks entered two Palestinian-controlled villages in the West Bank and killed four policemen. A fifth Palestinian, a taxi driver, was shot dead by heavy machine-gun fire from an Israeli tank on the edge of the West Bank town of Jenin, Palestinian medical sources and witnesses said.

A Palestinian security official said several tanks entered Ramin and Anabta east of Tulkarm and opened fire at a police post. Twenty-one arrests were made, one house in Anabta was burned and the village’s main road was destroyed. Other Palestinian officials said the Israeli Army ended its operation in Ramin three hours later but continued to occupy Anabta.

“Palestinian policemen who were dispersed out in the open fields heard the shooting, some tried to escape but it was too late. The Israeli soldiers were already at their heels and shot four of them in cold blood,” Anabta Mayor Hamdallah Hamdallah told Reuters.

Hamdallah said around 40 Israeli tanks, personnel carriers and jeeps, protected by two helicopter gunships, stormed into the village and firing was intensive.

The Israeli Army said it had been mounting an operation in Anabta when four Palestinians trying to escape in two cars opened fire on troops. “The troops retaliated and killed them.” Hamdallah said the arrested activists were from Palestinian President Yasser Arafat’s Fatah faction and from Hamas and Islamic Jihad.

Later, a Palestinian struck at a hitch-hiking post in Haifa crowded with soldiers returning to their bases at the end of the Israeli weekend. Police said casualties were low because the activist prematurely detonated explosives strapped to his body when officers began surrounding him after becoming suspicious. The bomber was badly wounded in the blast and police killed him. “They saw the man making movements with his hands and believed he was trying to detonate another bomb and they shot him dead,” northern police commander Yitzhak Borovsky told Israel Radio. Police said they found another bomb in a bag next to the body and defused it. Reuters TV pictures showed a firemen spraying water on to the burning corpse.

“We have not finished our operations. In light of what is happening, we may have to step up our activities,” Sharon told reporters.

Meanwhile, US special envoy Anthony Zinni said if Israel and the Palestinians do not make substantial progress in stopping escalating violence within 48 hours he will quit his task to find a lasting cease-fire, an Israeli official close to security talks said.

In Gaza City, Hamas supporters clashed with Palestinian police yesterday after security officers tried to arrest a Hamas man as part of a crackdown on activists.

Witnesses said dozens of Hamas supporters threw stones at the police when they moved on the home of the unnamed activist in the Gaza refugee camp of Shati to arrest him. A Palestinian policeman was wounded and two police vehicles were damaged in the stone-throwing incident, prompting the law enforcement agents to fire warning shots into the air to disperse the crowd, witnesses said.

During the disturbance, the man wanted by Arafat’s police force managed to escape, they said.