Israeli forces are using excessive, reckless violence in the occupied West Bank, killing dozens of Palestinians over the past three years in what might constitute a war crime, Amnesty International said on Thursday.

In a report entitled "Trigger Happy," the human rights group accused Israel of allowing its soldiers to act with virtual impunity and urged an independent review of the deaths.

The Israeli army dismissed the allegations, saying security forces had seen a "substantial increase" in Palestinian violence and that Amnesty had revealed a "complete lack of understanding" about the difficulties soldiers faced.

According to UN data, 45 Palestinians were killed in the West Bank between 2011-2013, including six children. Amnesty said it had documented the deaths of 25 civilians during this period, all but three of whom died last year.

"The report presents a body of evidence that shows a harrowing pattern of unlawful killings and unwarranted injuries of Palestinian civilians by Israeli forces in the West Bank," said Philip Luther, director of the Middle East and North Africa program at Amnesty International.

Amnesty said that in none of the cases it reviewed did the Palestinians appear to be posing any imminent threat to life. "In some, there is evidence that they were victims of wilful killings, which would amount to war crimes," the group said.

After a three year hiatus, Israelis and Palestinians resumed direct peace talks last July, which the Palestinians hope will give them an independent state on territory seized by Israel in the 1967 war, including the West Bank.

Although their decades-old conflict has become a low-intensity confrontation, violence still flares regularly, with Palestinians accounting for the vast majority of casualties.

The 87-page report focused only on violence in the West Bank, not the adjacent Gaza Strip. It highlighted a number of the deaths, including that of 21-year-old Lubna Hanash, who was shot in the head on January 23, 2013 as she left an agricultural college near the flashpoint city of Hebron.

Amnesty quoted witnesses saying a soldier opened fire some 100 meters from where she was standing. A female relative standing alongside her was shot in the hand. Neither had been taking part in any protest.

A few days earlier, 16-year-old schoolboy Samir Awad was shot three times, including in the back of the head, after staging a protest near the Israeli separation barrier that divides his village from its historical farmlands.

A third killing saw 15-year-old Waji al-Ramahi shot in the back from a distance of some 200 meters in December 2013 near the Jalazun refugee camp, Amnesty said.

Besides the numerous fatalities, Amnesty said at least 261 Palestinians, including 67 children, were seriously injured by live ammunition fired by Israeli forces in the West Bank over the past three years.

More than 8,000 Palestinians were seriously injured by other means, including rubber-coated metal bullets, since January 2011, the report said.

During this period, just one Israeli soldier was convicted of wrongfully causing the death of a Palestinian - an unnamed staff sergeant who shot dead a Palestinian while he was trying to enter Israel illegally in search of a job.

The staff sergeant received a one year prison sentence, with five months suspended, and was allowed to stay in the army, albeit at a lower rank, Amnesty said.

Three other investigations over the past three years were closed without indictments, five were closed but their findings were not revealed and 11 are still open.

"The current Israeli system has proved woefully inadequate," Amnesty's Luther said. "A strong message must be sent to Israeli soldiers and police officers that abuses will not go unpunished."

The military rejected Amnesty's findings, saying that the organization "exhibited an utter lack of understanding of the operational challenges the Israeli Defense Forces face."

A statement issued by the IDF Spokesman charged Amnesty with having "completely ignored the significant rise in Palestinian violence over the past year," citing 66 terrorist attacks including shootings, the planting of bombs, attempted stabbings and the murder of a soldier.

The statement went on to describe the non-lethal weapons it uses in order to keep the number of casualties to a minimum including the use of sirens, water cannons, tear gas and stun grenades. "The IDF holds itself to the highest professional standards, and equips itself accordingly. When suspicions arise that improper actions were taken or protocol was breeched, the IDF looks into this, investigates, and acts in accordance," the statement read.