Hamas’ military wing has claimed responsibility for the murder of four Israeli civilians, including a woman believed to be pregnant.
But American and Israeli officials have urged that Israel and the Palestinians do not let the terror attack derail the direct peace negotiations set to begin in Washington tomorrow.
A Hamas military spokesman praised the “heroic operation”, in which a Palestinian gunman shot at a car near the south Hebron hills. Seven children were left orphaned following the killings.
Security officials described the attack, which took place as the Ramadan fast was ending, as a well-planned ambush. The attackers are said to have paused to confirm that the victims were dead before fleeing.
One of the couples, Avishai Shindler and Kochba Even-Chaim, came from Kiryat Arba, while the other, identified as parents-of six Yitzhak and Tali Ames, lived in the West Bank settlement of Beit Hagai.
Guy Gonen, a paramedic at the scene, said on an Israeli news channel that he had seen “a car that was pierced with dozens of bullets and inside there were four bodies. There was absolutely no chance of helping."
With Prime Minister Benajmin Netanyahu and Palestinian president Mahmoud Abbas already in Washington, the White House condemned the attack but said it should not prevent the long-awaited meeting from taking place.
Hillary Clinton, the US Secretary of State, said: "This kind of savage brutality has no place in any country under any circumstances.”
Mr Netanyahu said he could only accept a peace plan that would allow Israel "to confront this kind of terror and other threats."
He said: "We will not let terror decide where Israelis live or the configuration of our final borders. These and other issues will be determined in negotiations for peace."
Silvan Shalom, Israel’s deputy prime minister, said: “While we are working to find ways to co-exist and create a reality of peace, there are those who continue to take the path of terror.
"The real obstacle to peace is terrorism and the extremists who will do anything to send the entire region up in flames.”
He said that for the talks to proceed successfully the Palestinian Authority must “fulfil its obligations in the territories.”
Right-wing politicians in Israel called on Mr Netanyahu to cancel the talks.
One Knesset member, Science and Technology Minister Daniel Hershkowitz said: "Unfortunately, this horrific attack once again proves that there is no partner on the Palestinian side.
“We must now consider if there is any point in holding these discussions."
A Likud politician, Ofir Akunis, added: "Every time Israel extends its hand for peace, the Palestinians make every effort to cruelly cut it off.”
Following the attack Israeli security forces have set up road blocks in the area.
Officials from the Palestinian Authority also condemned what happened and said the Palestinian security forces had launched an investigation and arrested 50 suspects.