International opprobrium was directed at Israel yesterday for its state-approved assassinations of suspected terrorists - a practice widely regarded as illegal.
A Foreign Office spokesman said the British government was shocked by what it described as the "murder" of one of Yasser Arafat's bodyguards by Israeli forces on Tuesday and of nine Israeli soldiers by a Palestinian yesterday.
"We condemn all acts of violence and urge both sides to refrain from reprisals. Neither side will gain from an escalation of the violence," the spokesman said.
Earlier, the outgoing Israeli prime minister, Ehud Barak, had publicly congratulated Israeli forces on the killing of the bodyguard, Massoud Ayad, whose car was rocketed by two helicopters.
Yesterday's attack, in which a Palestinian driver ploughed into Israeli soldiers at a bus stop, is thought to be a reprisal for Ayad's killing.
"This is exactly the kind of escalation we had feared," said a European diplomat close to recent peace negotiations.
Mr Barak's security adviser, Danny Yatom, defended the assassination of Ayad, telling Israel Radio: "We don't take pride in liquidating terrorists. We are in the midst of a battle, in the midst of a war against terrorism, and in this war we must strike at those who [threaten Israel]."
He described Mr Ayad, 53, an "arch terrorist" linked to the Lebanon-based organisation Hizbollah.
Britain has also backed one of the strongest statements yet from the European Union. In a declaration issued by current president Sweden, the EU said it "deplores the practice of so-called "eliminations" or extra-judicial killings of Palestinians carried out by Israeli security forces".
The EU, which is Israel's biggest trading partner, reiterated "its strongly held opinion that Israel's policy in this regard is unacceptable and contrary to the rule of law".
It continued: "The European Union urges Israel to cease this practice and thus respect international law."
The United States, while also condemning Palestinian violence, made clear its disapproval of the assassinations.
State Department spokesman Richard Boucher said: "The use of Israeli helicopter gunships, Palestinian attacks against settlements and motorists, the use of mortars by Palestinians and the targeted killings by the Israeli Defence Force ... are producing a new cycle of action or reaction which can become impossible to control."
Mr Boucher added that the new Secretary of State, Colin Powell, who is due to visit the Middle East next week, had spoken several times "about the need to avoid these kind of actions".
Apart from the risk of provoking reprisals which escalate the violence, liquidations have also caused unintended casualties.
Israel began selective assassinations of suspected senior Intifada militants in November, sending helicopter gunships to kill Hussein Abayat in Bethlehem on the same day that Mr Arafat was visiting the White House in Washington.
On that occasion, the rocket which hit the vehicle in which Mr Abayat was travelling also killed two elderly Palestinian women nearby and injured 10 other people.
More than 20 Palestinians have been liquidated by Israeli forces in targeted attacks.
Under international law, the assassinations are illegal unless the Israelis and Palestinians are considered to be at war.
Colonel Daniel Reisner, the Israeli military's head of international law, wrote recently in a briefing document: "International law actually only recognises two situations: peace and war. But life isn't as simple as that."
He continued: "We have reached the decision that the current situation has more of a semblance of war than of peace. As a result, we are also applying the principles applicable to warfare to the current situation."
This led him to conclude that the assassination of various Palestinian activists and militia leaders could be justified under the rules of war.
"You are allowed to target combatants," he wrote. "In the current situation, people who attack us have been identified by us as combatants. As a result we view them as legitimate targets. That specific individual falls under that category, therefore he was attacked and killed."
For the Israelis, one problem with this interpretation is that it would also have to apply equally to the Palestinians.
Palestinians would then be legally entitled to kill Israeli soldiers (as happened yesterday) and anyone else they regard as a combatant, such as armed settlers.
The death toll so far
February 13 2001: Massoud Ayad killed by rocket attack.
December 31 2000: Thabet Thabet shot dead.
December 17: Samih Maliabi killed by bomb - possibly a booby-trapped mobile phone.
December 14: Hani Abu Bakra shot dead by anti-terror police unit.
December 13: Abbas al-Ewiwi shot dead by snipers.
December 12: Yusuf Abu Swayeh ambushed by elite Kingfisher undercover unit.
December 11:Anwar Hamran shot by Israeli forces. Mahmoud al-Mughrabi shot by Israeli undercover unit.
November 23: Ibrahim Bani Odeh killed by bomb, most likely detonated by Israelis.
November 22: Jamal Abdel-Razak ambushed by Israeli soldiers.
November 9: Hussein Abayat died in rocket attack.
Source: The Palestinian Human Rights Monitoring Group.
© Guardian Newspapers Limited 2001