Israeli forces on Wednesday sealed off parts of the West Bank while Palestinian security officials said they arrested about 50 people after four settlers were gunned down just ahead of Middle East peace talks. And furious settlers vowed to flout a moratorium on settlement construction in protest against the attack as tensions rose ahead of a Washington summit hosted by US President Barack Obama to relaunch talks last suspended in 2008. Israeli soldiers carried out house-to-house searches in villages in the Hebron area, near the Kiryat Arba settlement where the two couples, including a pregnant woman, were killed on Tuesday evening. Access routes to the city of Hebron were closed by military roadblocks. Military Chief of Staff Lieutenant General Gabi Ashkenazi and other generals were at the scene where they conducted 'operational and intelligence situation assessments,' the military said. 'We are operating on a number of different levels since the event took place and will continue to act until we get a hold of the terrorists,' Ashkenazi said. Palestinian forces for their part arrested about 50 people during the night, a security official said. He said the suspects were supporters of Hamas, the Islamist movement that claimed responsibility for the attack. The victims of the shooting were identified as Yizhak and Talia Aimes, aged 45 and 47 respectively, Avishai Shindler, 24, and Kochba Even-Chaim, 37, and were believed to be settlers from the area. The bloodstained vehicle at the side of the road was riddled with what looked like dozens of bulletholes, with the Israeli military saying the attack appeared to be a drive-by shooting. The attack was claimed by the Ezzedine al-Qassam Brigades, the armed wing of Hamas which is vehemently opposed to the talks that Prime Minister Benjamin Netanyahu and Palestinian president Mahmud Abbas are to relaunch in Washington on Thursday. Netanyahu expressed outrage at the attack. 'There are seven new orphans that were added to the circle of grief in Israel,' he said ahead of talks with US Secretary of State Hillary Clinton. Abbas also condemned the attack, saying it was intended to 'disrupt the political process'. Following the attack, the main Israeli settlers association vowed it would immediately resume construction in the West Bank, which has been partly halted for the past 10 months in a measure imposed by the Israeli government under US pressure in a bid to promote the peace talks. 'This brutal attack again proved that despite what might be going on in Washington right now, the Palestinians have no goal to create a peaceful state for themselves but are entirely driven to destroy our state and our people,' said Naftali Bennett, director general of the Yesha Council. 'The only response that will show our resolve against terror is to commit ourselves to building, and effective Wednesday evening we will bring this senseless freeze to an immediate end,' he said in a statement. Defence Minister Ehud Barak urged the settlers to exercise restraint, army radio said. The settlement issue has been one of the thorniest in peace efforts and will be addressed during the upcoming negotiations, the first direct talks in 20 months. The Israeli government is under strong pressure at home to allow construction to resume when the partial moratorium on building in West Bank settlements ends on September 26. The Palestinians insist this would torpedo the peace efforts. Deputy parliamentary speaker Danny Danon on Wednesday urged Netanyahu to stick to his earlier promises not to renew the construction moratorium. 'I remind the prime minister of his repeated clear commitments to the citizens of Israel that we will resume building our communities throughout our country on September 26, 2010,' Danon said in a statement. 'Israel's voters and Likud party supporters will not tolerate any sort of 'compromise' agreement that infringes on the basic rights of families and communities to build homes and schools in their towns and cities,' he said. Tuesday's shooting was the first fatal attack on Israelis in the West Bank since June 14, when a policeman was killed and two others were wounded, also in the Hebron area. 