An Israeli helicopter again fired missiles into a crowded area of the Gaza Strip last night in an assassination of a Palestinian militant. Children were among the 23 wounded by the missile strike.

The killing came despite an opinion poll published yesterday which found that 67 per cent of Israelis want the assassinations to stop, at least temporarily, to give the peace process a chance.

But the Israeli government pressed on. The deputy defence minister, Zeev Boim, vowed that the government would "wage a war to the bitter end" against the Hamas militant group. Hamas leaders have threatened to bomb Israel "to rubble". Yesterday's was the fourth assassination attempt by the Israeli army in Gaza this week.

The United States called once again for restraint from Israel, its previous calls having apparently fallen on deaf ears. "We are all anxious to see restraint and we understand that it's important to get the terror down," said Colin Powell, the US Secretary of State, adding a plea to Hamas to stop its attacks: "If the terror goes down, then the response to terror will no longer be required."

The victim of yesterday's assassination, 26-year-old Fuad al-Lidawi, was not a senior Hamas militant. The Israeli army claimed that he and the others travelling in the car in which he was hit were members of a Hamas squad on its way to fire rockets across the fence into Israel.

But it appears the Israeli military may have made a mistake. Mr Lidawi was a bodyguard for a senior leader in Hamas's armed wing, Ahmed al-Ghandour. It is possible Mr Ghandour was the intended target, but he was not travelling in the car when it was hit.

Assassinations are becoming so frequent in the Gaza Strip that Gazans flee their cars when they hear a helicopter coming. The past week has seen hopes for the road-map peace plan sponsored by President George Bush dashed in a welter of violence.

A week of assassination attempts began when the Israeli Prime Minister, Ariel Sharon, ordered the assassination of the most prominent leader in Hamas' political wing, Abdel-Aziz Rantisi. That attempt failed, but it earned Mr Sharon a sharp rebuke from the White House.

Before the attempt on Mr Rantisi's life, Hamas leaders were considering resuming talks with the Palestinian Prime Minister, Abu Mazen, about a possible ceasefire.

After the assassination attempt, Hamas promised an "earthquake" of revenge. A day later, 16 people were killed in a suicide bombing on a bus in Jerusalem.

The Israeli government claimed Mr Rantisi's assassination had been ordered because an opportunity presented itself. But yesterday's poll for Yedioth Ahronoth newspaper found that 40 per cent of Israelis believe Mr Sharon ordered the assassination in a deliberate attempt to sabotage the road-map and wreck the peace process.

Many innocent bystanders, including children, have been killed in this week's assassinations, in which Israeli helicopters have fired into civilian areas with abandon. Scores of civilians have been wounded.

In one assassination earlier this week, Palestinian witnesses said the Israeli helicopter had fired a second time into a crowd of civilians who gathered to help the wounded.