TEL AVIV - Washington has questioned Israel over a deadly West Bank raid over the weekend that killed three members of Palestinian Authority president Mahmud Abbas's Fatah movement, an Israeli official said on Sunday.
Washington has passed on the Palestinians' concerns over why the raid was carried out without their forces being given an opportunity to arrest the men, the official said.
Israel said the three men shot dead in Nablus on Saturday were behind the killing of an illegal Jewish settler in the Israeli-occupied Palestinian West Bank two days earlier.
But the Israeli military confirmed that none of the Palestinians fired any shots at the troops that came to arrest them at three different locations and said only one of them was armed.
Family members of the three men said the troops entered without warning and killed all three in cold blood, insisting none had resisted arrest.
One of the men was a member of the Al-Aqsa Martyrs' Brigades, a group loosely linked with Abbas's Fatah movement, and the other two were Fatah activists, Palestinian security officials said.
Israel said that it had notified Palestinian security forces just before the raid was carried out, but the Palestinian Authority said the operation dealt a blow to its own efforts to maintain security.
A US official quoted by the left-leaning Haaretz daily also said on Sunday that Washington had contacted Uzi Arad, a senior aide to hardline Prime Minister Benjamin Netanyahu, over the incident.
"We expressed our concern and encouraged both sides to continue their security cooperation," he was quoted as saying.
"We talked to both sides in order to get full information about what happened," he added.
Netanyahu meanwhile praised the commando operation on Sunday.
The Israeli human rights organisation, B'Tselem, called for an investigation into the killings, saying they could have been in fact "executions."
"Based on testimony from the site (of the raids), it appears that at least two of the three men were not armed and that they were shot and killed as they tried to surrender," B'Tselem spokeswoman Sarit Michaeli said.
"There are good reasons to believe that these were executions."
Palestinian prime minister Salam Fayyad denounced the operation as a deliberate attempt to undermine recent security gains.
"This operation represents a dangerous escalation, and can only be seen in the context of targeting the security and stability that the Palestinian Authority has been able to bring about," he said.
Abbas's spokesman Nabil Abu Rudeina accused Israel of trying to "drag our people into a spiral of bloody violence."
At funeral processions for the three men hundreds of people took to the streets.
The democratically elected Hamas movement in Gaza said Abbas' "illegitimate" government was partly to blame for the killings because of its cooperation with Israel.
Meanwhile, another three Palestinians were killed in an air strike on Gaza, local medics and the Israeli military said.
A military spokeswoman said the three were militants who ignored warning shots, but medics and Hamas border guards stationed nearby said they were civilians scavenging for scrap metal.