The Islamist group Hamas, which controls the Palestinian enclave of Gaza, abducted, tortured and even killed several Palestinians suspected of being Israeli collaborators during last year’s 50-day war in the region, according to a new report published Wednesday by Amnesty International. The rights group has, in the past, also accused the Israeli military of committing war crimes during its assault on the strip, when over 2,100 Palestinians, most of them civilians, and over 70 Israelis, were killed.

“In the chaos of the conflict, the de facto Hamas administration granted its security forces free rein to carry out horrific abuses including against people in its custody,” Amnesty International’s Middle East and North Africa Director Philip Luther, said, in a statement. “It is absolutely appalling that, while Israeli forces were inflicting massive death and destruction upon the people in Gaza, Hamas forces took the opportunity to ruthlessly settle scores.”

The report includes allegations that the Islamist group carried out summary killings of at least 23 people, including many who had been held in Hamas’ custody since before the conflict broke out in the Gaza Strip. Of these, many are believed to have been tortured to extract false confessions.

“In one of the most shocking incidents, six men were publicly executed by Hamas forces outside al-Omari mosque on 22 August in front of hundreds of spectators including children,” Amnesty said, in the report. “Hamas announced the men were suspected ‘collaborators’ who had been sentenced death in ‘revolutionary courts.’” 

In addition to those accused of helping Israeli forces, several others were tortured and executed for being members and supporters of Fatah -- the main Palestinian rival political party in the region, Amnesty alleged, adding that Hamas used the conflict as an excuse to carry out executions without due process.

“The Hamas leadership repeatedly calls for rights and justice for Palestinians in Gaza and elsewhere. But they do not always act in a manner that reflects respect for rights, justice and the rule of law,” Luther said, in the statement.

Refuting the allegations leveled against it, Hamas reportedly said that other “Palestinian resistance factions” were the ones involved in the execution of Israeli collaborators.

“Hamas did not claim responsibility for the killing of collaborators during the war,” Mushir al-Masri, a spokesman for the group, told the New York Times. “The Amnesty report about Hamas needs to be more precise.”

The Amnesty report comes at a time of renewed violence in the conflict-torn Gaza Strip. After a rocket was allegedly fired from Gaza on southern Israel, the Israeli military responded by striking “terrorist locations” in the strip early on Wednesday.

“Hamas better restrain any attempts to open fire toward Israel or provoke it; otherwise we will have to act more forcefully,” Israeli Defense Minister Moshe Ya'alon said Wednesday, according to Haaretz. “I wouldn't advise anyone to test us.”