Four Palestinians were killed and nearly 20 others injured early Tuesday in raids by Israeli forces in the occupied West Bank, the Palestinian Health Ministry said.

"There are three dead and 19 wounded, three of them seriously, by Israeli fire in Nablus," the ministry said in a brief statement referring to a city in the occupied West Bank.

The ministry later reported that another Palestinian was killed by Israeli fire, this time in Ramallah, home to the Palestinian Authority's headquarters in the central West Bank.

The Israeli army confirmed in a joint statement with police and intelligence agencies that they had conducted a large-scale night operation in Nablus, raiding a "hideout apartment... that was used as a headquarters and explosives manufacturing site".

"The site was used by the main operatives of the 'Lion's Den' terrorist group," the statement said, referring to a new group of young Palestinian fighters who have carried out anti-Israeli operations in Nablus in recent weeks.

"During the activity, multiple armed suspects were hit and Palestinian reports indicate that were multiple injuries."

The Lion's Den -- called "Areen al-Ossoud" in Arabic -- is composed of young Palestinian fighters, some of whom are affiliated with groups such as Fatah, Hamas and Islamic Jihad.

They claimed responsibility for a deadly attack on an Israeli soldier two weeks ago in the occupied West Bank.

Their late leader Ibrahim al-Nabulsi, nicknamed "The Lion of Nablus", was known for galvanising the youth before he was shot dead by Israeli forces in August. He has since become a folk hero to Palestinians on social media.

In the aftermath of Nabulsi's death, the Israeli army tightened its grip on the city, setting up controls to identify people leaving and constantly scanning the skies above with observation drones.

On Saturday night, a Lions' Den fighter, Tamer al-Kilani, was killed in the Old City of Nablus by an explosion attributed by the group and the Israeli press to a bomb remotely activated by the Israeli army. The army did not comment on these claims.

After Tuesday's early morning clash, Palestinian President Mahmud Abbas is establishing "urgent contacts in order to stop this aggression against our people", his spokesman Nabil Abu Rudeinah said in a statement.

The Palestinian Islamic Jihad also said in a statement its "fighters were involved in violent clashes" with Israeli forces in Nablus and threatened Israel with reprisals "against these crimes" there.

- 'War crimes' -

Violence has surged in recent months in the northern West Bank, Palestinian territory occupied since 1967 by Israel, especially in the areas of Nablus and Jenin.

Israeli soldiers have stepped up operations in both cities since March in the wake of deadly anti-Israeli attacks.

These raids, often accompanied by clashes with the Palestinian population, have resulted in more than a hundred deaths on the Palestinian side, the highest death toll in the West Bank in nearly seven years, according to the UN.

Since the beginning of the month, more than 20 Palestinians and two Israeli soldiers have been killed, according to an AFP report.

Amnesty International on Tuesday called for an International Criminal Court probe into possible "war crimes" committed by both Israeli and Palestinian militants in August during deadly fighting in the Gaza Strip, a Palestinian enclave under Israeli blockade since 2007.

Thirty-one civilians were among the 49 Palestinians killed in the Gaza Strip during the three-day conflict, the global rights group said in a new report, which looked at three incidents in particular -- two attributed to Israeli forces and one to Palestinian factions.

"The three deadly attacks we examined must be investigated as war crimes," said Agnes Callamard, Amnesty International's Secretary General. "All victims of unlawful attacks and their families deserve justice and reparations."

Amnesty urges ICC probe of possible Gaza war crimes

Amnesty International on Tuesday called for an International Criminal Court (ICC) probe into possible war crimes committed in August by both Israeli forces and Palestinian militants during deadly fighting in Gaza.

Thirty-one civilians were among the 49 Palestinians killed in the Israeli-blockaded Gaza Strip during the three-day conflict, the global rights group said in a new report.

The London-based organisation pressed the ICC to "urgently investigate any apparent war crimes committed during the August 2022 Israeli offensive" in the Palestinian enclave.

"Amnesty International has collected and analysed new evidence of unlawful attacks, including possible war crimes, committed by both Israeli forces and Palestinian armed groups," it said.

The report detailed a strike that hit the Jabalia refugee camp in northern Gaza, killing seven civilians.

The bombing was "likely to have been caused by a rocket launched by Palestinian armed groups that misfired", Amnesty said.

Fighting began on August 5 when Israel targeted the Islamic Jihad militant group in what it said were pre-emptive strikes to avert attacks.

The Palestinian organisation responded with barrages of rocket fire that did not result in any Israeli casualties.

Amnesty's research found that an attack in which five children were killed at a cemetery "was likely to have been carried out by an Israeli guided missile fired by a drone".

A third incident Amnesty said may amount to a war crime was Israeli tank fire on a house in the southern Khan Yunis area, which killed one civilian.

The International Criminal Court has opened an investigation into the Israeli-Palestinian conflict, expected to focus in part on possible war crimes committed during the 2014 conflict in Gaza.

The probe is supported by the Palestinian Authority, but Israel is not an ICC member and disputes its jurisdiction.

The violence in August was preceded by four wars between Israel and Palestinian militants in Gaza since 2008.

The Palestinian enclave has been under a crippling Israeli-led blockade since 2007, imposed after the Islamist movement Hamas took control of the territory.

Hamas said its militants did not participate in the August conflict.