Israeli troops shot dead two Palestinians in the occupied West Bank today amid a new descent into violence.

The two, who Palestinians claimed were detained while ploughing a field of olive trees near Nablus, were shot several times. Palestinian officials said both were 17. The Israeli military said they had tried to stab a soldier.

The deaths bring to five the number of people killed in the region in the past week.

As the violence placed further strain on US efforts to get peace talks under way, a spokesman for the Israeli prime minister, Binyamin Netanyahu, said he would be meeting Barack Obama in the US on Tuesday.

Netanyahu's visit comes at a time of heightened tensions between Israel and the US over a controversial Jewish housing project in east Jerusalem. The project embarrassed Washington because it was announced while the vice-president, Joe Biden, was in Jerusalem to kickstart Israeli-Palestinian talks.

Earlier today, relatives buried the bodies of two teenage Palestinian boys who were shot dead by Israeli troops yesterday during a demonstration against settlers in the village of Iraq Burin, also near Nablus. Last week, a Thai worker in southern Israel was killed by a rocket fired by militants in Gaza.

Witnesses in Iraq Burin described how Israelis from the nearby hilltop settlement of Brakha came down on to the village's farmland yesterday. Israeli troops were deployed and Palestinian boys threw stones at the soldiers.

Mohammad Qadus, 15, and Osaid Qadus, 17, were shot dead inside the village shortly after they arrived back in Iraq Burin on a local bus. Neither had taken part in the demonstration, witnesses in the village said.

Amir Aref, 16, a friend of both boys, tried to drag them to safety. He described how he saw Osaid sitting on the ground in front of a store. "I was telling him: 'Stand up, stand up.' But he refused to answer," Aref said. "I looked at him. Blood was coming down from a small hole in his forehead, his brains were coming out."

He then turned to Mohammad and saw him lying on the road nearby. "I carried him and took him into the village in my arms," Aref said. "I looked at him and he said 'Amir', then blood came out of his mouth. He gasped and then he died."

Witnesses and doctors at the Nablus speciality hospital, where the boys were treated, said both were hit by what appeared to be live rounds that left small entry wounds.

The Israeli military said in a statement there had been a "violent and illegal riot" in the village and that soldiers "responded with riot dispersal means". It said troops fired tear gas and rubber bullets, but denied firing live rounds. "Live fire was not used," the military said.

However, a hospital x-ray of Osaid Qadus, seen by the Guardian, showed a bullet lodged in his brain.

Ahmed Hamad, a doctor at the hospital who treated the two, said the x-ray showed a "classic, pure metallic bullet". He said both boys had injuries with small entry wounds.