The White House and European Union foreign policy chief Catherine Ashton have strongly condemned the August 31 2010 attack in which a Palestinian gunman shot dead four Israelis just as Israeli and Palestinians made final preparations for their first face-to-face peace negotiations in close to two years.
 
"With this unacceptable attack, the enemies of peace have tried to derail the Middle East peace talks," Ashton said. "But we are determined not to let these enemies of peace have their way."
 
Ashton called on the parties to the talks, which are scheduled to begin in Washington on September 2, "to engage with determination in the negotiations".
 
"It is imperative that both parties keep calm and exercise restraint even through difficult times to make progress towards a just, lasting and comprehensive peace in the region."
 
The European Union remains committed, along with its partners in the Quartet as well as Arab countries, to support successful negotiations, which are in the interest of Israelis and Palestinians, the peoples of the region and the international community, she said.
 
The Islamist militant group Hamas says its military wing carried out the August 31 attack, the Voice of America reported. 

Israeli police spokesman Micky Rosenfeld says the gunman opened fire on the vehicle near the city of Hebron.

"An attack was carried out against a number of Israelis [who] were driving in a vehicle.  Unfortunately, as a result of the shots that were fired, all four of them sustained critical injuries, the result being four Israelis killed -two of them men, two of them women," Rosenfeld said.

Hebron has been a frequent flashpoint in the conflict between Palestinian residents and tens of thousands of Jewish settlers who live inside the city and in surrounding settlements.

Police say the Israeli victims were residents of a nearby settlement. 

The talks have drawn opposition from within the Palestinian Authority led by president Mahmoud Abbas.  Some Palestinians have demanded that the Palestinian leader not attend the talks unless Israel guarantees that it will stop the building of Jewish settlements in the Israeli occupied West Bank.

Israel has refused to commit to a permanent construction freeze, saying that it wants to negotiate without preconditions. 

Abbas has come under harsh criticism from some Palestinians over his government's security co-operation arrangements with Israel. 

Within hours of the shooting, Hamas' military unit claimed responsibility for the attack. 

Reporting for VOA, journalist Mohammed Dawwas in Gaza says Hamas' leaders called on hundreds of Palestinians to a rally late on August 31.

"This rally is in the north of the Gaza Strip, in the Jabalya refugee camp, the biggest, most crowded refugee camp in the Gaza Strip.  People are out celebrating the killing of four settlers in the West Bank," Dawwas said.

Hamas condemns all negotiations with Israel and has strongly criticised Abbas' decision to attend the talks. 

Israel's defence minister Ehud Barak issued a statement promising a harsh response for the killings near Hebron, saying that Israel will "exact a price" from those responsible.  He said the attack was aimed at sabotaging the peace talks.
 
The White House condemned the attack and said that it was crucial for peace efforts to continue.
 
According to VOA, US president Barack Obama is to host a dinner on September 1 for Israeli and Palestinian leaders, as well as Egyptian president Hosni Mubarak and Jordan's king Abdullah. 

Israeli prime minister Benjamin Netanyahu and Palestinian president Abbas agreed to meet after months of pressure from the Obama administration, which considers the Middle East peace process one of its highest foreign policy priorities.