On the eve of a US sponsored peace summit in Washington, unidentified gunmen killed four Israelis today in the occupied West Bank in the worst such attack in many months, Israeli medics and police said.
An Israeli police spokesman said "we can confirm there are four dead at the scene," after the Israelis' vehicle was ambushed after dark near the flashpoint West Bank city of Hebron.
He said the incident occurred near the Kiryat Arba settlement, and that "shots were fired at them" while they rode in a vehicle. Israel's Channel Two television said they had been shot from a passing vehicle.
Medics said two men and two women, one of them pregnant, were killed. It was not immediately clear whether they were all civilians.
The Hamas armed wing said it would carry out more operations after claiming responsibility for the shooting.
"This attack is a chain in a series of attacks, some have been executed, and others will follow," Abu Ubaida, spokesman for the group, said.
The Israeli and Palestinian leaders are due to meet US President Barack Obama for dinner at the White House tomorrow, and open formal talks on September 2nd - their first direct negotiations for nearly two years.
Prime minister Benjamin Netanyahu will tell US Secretary of State Hillary Clinton that the attack shows there should be "no compromise" on Israeli security demands in peace talks, a government spokesman said tonight.
Spokesman Nir Hefez said as Mr Netanyahu arrived for the new peace talks in the United States: "The criminal murder proves again the need to stand firmly on Israel's stringent security demands, and there will be no compromise on them."
Mr Hefez said Mr Netanyahu had, in response to the killing of four Israelis in a roadside shooting near the West Bank town of Hebron, "ordered (Israeli) security forces to act without political limits to catch the murderers and react aggressively."
Earlier Israeli defence minister Ehud Barak promised that Israel would "exact a price" from those who shot dead the four Israeli civilians.
"This is an apparent attempt by lowly terrorists to sabotage the attempt to achieve a diplomatic process and to try to hurt the chances of the talks opening in Washington" this week, Mr Barak added, in a statement issued to reporters.