Four Palestinians died in disputed incidents on Saturday and Sunday
An Israeli rights group is calling for an investigation into the deaths of two Palestinians it suspects were killed by live fire, contrary to military claims.
The Israeli army said only rubber- coated rounds were used at the protests on Saturday in which Mohammed and Osayed Qadus were fatally injured.
But the group, Btselem, said pictures and an x-ray showed wounds inconsistent with rubber-coated bullets.
The military says "violent and illegal riots" were taking place at the time.
The shooting took place while protests, at which stones were thrown at Israeli security forces, were being held in the village of Iraq-Burin near the town of Nablus, in the north of the West Bank on Saturday.
Palestinian Authority President Mahmoud Abbas condemned the deaths, saying that Israel's response to diplomacy was violence.
"The Israeli escalation and the killing of Palestinians on a daily basis is the actual response of the Israeli government to the Palestinians, the Arabs and to American peace efforts, and an answer to the Quartet's statement," he said in a statement.
'False reporting of facts'
During the incident 15-year-old Mohammad Qadus sustained chest injuries. He was dead by the time he arrived at hospital.
X-ray apparently of Osayed Qadus' head showing a bullet lodged inside (Source: Btselem)
Photographs obtained by Btselem from the hospital show wounds in both his chest and back, which Btselem's director, Sarit Michaeli, said were "completely inconsistent" with the use of rubber-coated bullets.
"It's unheard of that a rubber-coated bullet will penetrate and then exit the body," said Ms Michaeli.
The hospital also showed Btselem an x-ray, which it said showed the skull of Osayed Qadus, 18, who died from his injuries on Sunday morning.
"There is very clearly a bullet inside the skull," said Ms Michaeli.
"The bullet is consistent with live ammunition. It is completely inconsistent with rubber-coated steel bullets of the two types used by the IDF [Israeli Defence Forces] - there are cylindrical and circular ones, neither looks anything like what you can see in the x-ray."
The organisation is calling for a military criminal investigation, not just into "who shot them and why", but also into the "suspected reporting of false facts by the soldiers who participated in the events", Ms Michaeli said.
On Saturday, the Israeli military said live fire had not been used.
On Monday, spokeswoman Avital Liebowich told the BBC that had been the conclusion of an initial investigation, and maintained that the army "did not give any orders to use live fire".
She said a "debriefing" was taking place at brigade level regarding the incident.
The family of Osayed Qadus told the BBC both youths were on their way home from college, and were not taking part in the clashes, when they were shot.
Btselem also wants an investigation into an incident on Sunday, in which two Palestinians were shot dead by Israeli security forces in disputed circumstances.
The military initially said the Palestinians had tried to stab a soldier. Later reports said they had attacked security forces with pitchforks and an axe.
On Monday Ms Liebowich said the two Palestinians were carrying a container filled with rocks and a medical syringe, and possibly also pitchforks.
"The soldiers understood they were about to get hurt and opened fire to save themselves," she said.
But a local Palestinians told the BBC the two men were arrested before they were killed, on the basis of a phone call a village elder says he received from the military saying they were being held, before later hearing that they had been shot dead.
Ms Liebowich denied accusations from Palestinians that the military was provoking tensions by using heavy handed tactics during clashes.
"We see in the past several weeks Palestinian extremist factions inciting the entire area... that's why we see an increase in the protests, in the violence, this is the real reason for the flaring up - it has nothing to do with the Israeli military's rules of engagement," she said.