Violence escalates in Middle East

The Middle East's deadly spiral of violence swept on yesterday as each side claimed revenge for attacks by the other and vowed more reprisals.

Israel warned of a response "that will eliminate this ongoing threat" after a Palestinian gunman opened fire on a bus queue in central Jerusalem, injuring 35 people, six seriously.

The militant Hamas group simultaneously promised "all-out war" against Israel on all fronts - a signal that it will probably resume suicide bombings - after Israeli troops shot dead four of its members at a house in Nablus.

In a further sign of disintegration on the West Bank, Palestinian police used live ammunition as a Palestinian crowd, some 2,000-strong, stormed a prison. One man died from his injuries.

The Jerusalem shooting came during the afternoon rush hour, near a pedestrian mall where Hamas suicide bombers killed 10 Israelis in December. Eyewitnesses said a lone gunman got out of a taxi and fired into a bus queue. People fled for cover in shops under a hail of bullets.

Police shot dead the gunman before he could reload.

Dore Gold, an adviser to the prime minister, Ariel Sharon, said Israel would "respond appropriately in a manner that will eliminate this ongoing threat to the people of Israel".

The al-Aqsa Brigades, a Palestinian militia linked to Yasser Arafat's Fatah movement, claimed responsibility and named the gunman as Said Ramadan, 24, from Nablus.

It said the shooting was revenge for an attack earlier in the day when Israeli troops, on an incursion into the West Bank town of Nablus, shot dead four Hamas members.

Army spokesmen said the four died in a gun battle after an army unit arrested nine Palestinian fugitives and stormed a housing block suspected of hiding workshops for making explosives.

But Palestinians said it was an execution. They cited walls blackened by explosive charges and blood-soaked mattresses in the flat where the men lived. One of those killed was found in a shower in his underwear, they said.

The director of Nablus hospital, Hussan Johari, said all the men were shot at close range, most in the head.

The Israeli army dismissed charges of assassination but admitted that at least three of the four were wanted for bomb attacks in Israel and the West Bank.

Hamas sources confirmed that one of the dead, Hassan al-Sarkaji, was a top commander in Hamas's military wing, Izz al-Din al-Qassam.

In a statement, Hamas said: "This massacre has opened the door wide to total war that will hit the Zionists everywhere and with all means at our disposal."

That has been taken to mean that Hamas will abandon its month-long moratorium on suicide attacks inside Israel.

On news of the killings, hundreds of Palestinians stormed the gate of the Palestinian Authority's Nablus prison, demanding the release of 25 Hamas members interned as part of Mr Arafat's efforts to maintain a ceasefire.

PA police dispersed the protesters with tear gas, stun grenades and live ammunition. A Palestinian man, Abdel Nasser Swaftah, 37, later died from head injuries.

Calm was restored when the police freed one Hamas prisoner, a brother of one the four dead men.

In a decision that may soon be reversed, the army pulled out of most of Tulkarm yesterday, which it reoccupied on Monday as a reprisal for a Palestinian shooting that left six Israelis dead at a Bat Mitzvah in the Israeli town of Hadera last week. One Palestinian was killed during the incursion.