Prime Minister Binyamin Netanyahu heard about the the Hamas shooting attack in the West Bank which killed four Israelis along Route 60 while en route to Washington to relaunch direct talks with the Palestinians, and said upon landing that he would tell US Secretary of State Hilary Clinton that this “criminal attack” proves again the need for Israel to stand steadfastly by its security demands. Netanyahu said that his heart goes out to the families of the victims, and that terrorism would not determine Israel’s borders or the future of the settlements. RELATED:Analysis: An attempt to torpedo peace talksAnalysis: What if he was opposition leader?Netanyahu spoke on the plane with Defense Minister Ehud Barak, Shin Bet (Israel Security Agency) head Yuval Diskin and Chief of General Staff Lt.-Gen. Gabi Ashkenazi. Netanyahu, according to his office, directed the security branches to act “without any diplomatic constraints against the murderers, and act aggressively against those who sent them.”Officials in the prime minister’s entourage said that while Netanyahu was outraged by the attack, there was no intention of canceling the trip and returning to Israel.The US made a statement on Tuesday night in the wake of the attack. The statement by the Press Secretary read:"The United States condemns in the strongest possible terms the terrorist attack today perpetrated by Hamas in which four Israelis were killed in the southern West Bank. We express our condolences to the victims’ families and call for the terrorists behind this horrific act to be brought to justice. We note that the Palestinian Authority has condemned this attack." "On the eve of the re-launch of direct negotiations between Israelis and Palestinians, this brutal attack underscores how far the enemies of peace will go to try to block progress. It is crucial that the parties persevere, keep moving forward even through difficult times, and continue working to achieve a just and lasting peace in the region that provides security for all peoples."In response to the attack, Palestinian Authority President Mahmoud Abbas said on Tuesday night that he "condemns all acts that target Palestinian and Israeli civilians." Abbas said that the attack in the Hebron attack was designed to "disrupt the peace process. and can't be regarded as an act of resistance."Prime Minister Salam Fayyad said that the attack was intended to undermine the PLO's efforts to rally international support for the Palestinians's demands. He said that the attack was in contradiction with the national interests of the Palestinians and the PA's strategic vision, "which combines political struggling with completion of the building of state institutions." Fayyad called on Palestinians to abandon violence and maintain the path of peaceful popular resistance against settlements The terror attack was believed to have been aimed at torpedoing the Israeli-Palestinian peace talks, set to kick off on Wednesday in Washington. Hamas military wing spokesman Abu Obeida told The Associated Press late Tuesday that Hamas carried out the attack.The four victims, described by a settler spokesman as a couple and two hitchhikers – were driving on Route 60 near the entrance to Kiryat Arba when their vehicle came under fire. The victims were named as Yitzhak Ames, 47, and his wife Tali Ames, 45, Kochava Even-Haim, 37, and Avishai Schindler, 24, all from Beit Hagai. The Ames couple had six children, including a one-and-a-half-year-old toddler.Zaka volunteer Momy Even-Haim was dispatched to the scene of the attack with his colleagues, when to his horror he discovered that his wife was among the dead.“We saw a crying volunteer, and at first we did not understand what was happening – he has seen many disasters before,” Zaka volunteer Isaac Bernstein told The Jerusalem Post.“Then he started shouting, ‘That’s my wife! That’s my wife!’ We took him away from the scene immediately,” Bernstein added. Even-Haim was taken to his home in Beit Hagai by his colleagues.“When we arrived on the scene, all four doors of the car were open and four bodies were strewn on the road,” Magen David Adom paramedic Guy Ronen told The Jerusalem Post. “We saw that the vital organs had been struck by a very large number of bullets, and that there was no chance of saving their lives,” he added.“It was a very difficult scene. We had learned to forget scenes like this in recent years,” Ronen said.The IDF was investigating two possibilities – that Palestinian terrorists had laid an ambush alongside the road or that the shots were fired from a passing car. IDF troops immediately launched searches for the perpetrators and the Central Command raised its level of alert, out of fear that Palestinian terrorists will increase efforts to perpetrate attacks in the coming days with the goal of torpedoing the peace summit in Washington. According to eyewitness reports, the terrorists succeeded in hitting the passengers in their initial fire, but then approached the car and shot the occupants again at close range. Following the attack, the Israel Police Operations Branch sent out an order to all officers in the Judea and Samaria district calling on them to increase their awareness and be on the look out for potential terror attacks, while maintaining security in the area.Barak was also briefed on the attack by Ashkenazi and Diskin.“This is a very grave incident,” Barak said. “The IDF and Israeli security forces will do everything they can to capture the murderers.“Israel will not allow terrorists to lift their heads and will exact a price from the murderers and those who sent them. This is likely an attempt by terrorist lowlifes to stymie the diplomatic process and to hurt the chances of the talks opening in Washington.”Deputy Prime Minister Silvan Shalom, who is acting premier during Netanyahu’s absence, released a statement, saying that he was in close contact with Barak and with Netanyahu’s military attache and was constantly receiving updates.“Unfortunately it has once again been proven that while we are working to find ways to advance peace and coexistence, there are those who will continue trying to commit acts of terror and murdering innocents,” Shalom said.“Now it is clearer than ever that the real obstacles to peace are terror and the extremists who would do anything to inflame the entire region. The PA must fulfill its obligations in the territories.”The head of the Civil Administration in Judea and Samaria, Brig.-Gen. Yoav Mordechai, spoke with his Palestinian counterparts and updated them regarding the attack. PA security forces were conducting their own investigation into the shooting.While the IDF apparently did not have specific intelligence regarding the Tuesday night’s shooting, there had been concern that terror groups would use the launching of direct peace talks to perpetrate attacks in the West Bank. Ashkenazi and OC Central Command Maj.-Gen. Avi Mizrachi had toured Judea and Samaria earlier this week and met with brigade commanders. Ashkenazi asked the commanders to raise their level of vigilance for the duration of the summit in Washington out of fear that either Hamas, Islamic Jihad or even al-Qaida-affiliated elements would launch attacks against Israel. The forces were also asked to avoid friction with the Palestinian civilian population and to demonstrate sensitivity at the crossings between Israel and the West Bank.“We’re talking about one of the worst terrorist attacks in the past few years,” said Naftali Bennet, director-general of the Council of Jewish Communities of Judea, Samaria and Gaza.“We’re asking that the prime minister immediately turn the plane around and come back to Israel. It’s not possible, while we’re holding funerals, that he can stay there. And we’re calling on him, tomorrow morning, to renew the building in Judea and Samaria,” he said.The council announced Tuesday night that it would respond to the attack by unilaterally ending the construction freeze and starting to build on Wednesday.On Tuesday night after the attack, several youths gathered at the entrance to Kiryat Arba protesting the talks in Washington.Right-wing MKs also called for the talks to be frozen.Gil Hoffman, Herb Keinon, and Hilary Leila Krieger, and Melanie Lidman contributed to this report.