Amnesty International accused Hamas militants Wednesday of abducting, torturing, and carrying out summary executions of Palestinians during last year's conflict in the Gaza Strip. 

The report, the last of four released by the human rights group detailing events during the fighting, said that at least 23 Palestinians were shot and killed by Hamas, which rules Gaza, while dozens more were arrested and tortured. Amnesty said those targeted were either political rivals of Hamas, including members of the Fatah party of Palestinian President Mahmoud Abbas, or people the militant group had accused of cooperating with Israel.

The report detailed one particularly brutal spate of violence, which took place this past Aug. 22. 

"In one of the most shocking incidents, six men were publicly executed by Hamas forces outside al-Omari mosque ... in front of hundreds of spectators, including children," the report said. Hamas had announced the men were suspected "collaborators" who had been sentenced to death in "revolutionary courts," the rights group added.

"The hooded men were dragged along the floor to kneel by a wall facing the crowd, then each man was shot in the head individually before being sprayed with bullets fired from an AK-47," the report said of the August incident.

In one section of the report, testimony from the brother of Atta Najjar, an ex-Palestinian Authority policeman imprisoned since 2009 and killed by Hamas last August, described the violence done to him in captivity.

"His arms and legs were broken ... his body was as if you’d put it in a bag and smashed it ... His body was riddled with about 30 bullets," the brother was quoted as saying. "He had slaughter marks around his neck, marks of knives ... And from behind the head - there was no brain. Empty ... It was difficult for us to carry him ... He was heavy, like when you put meat in a bag; no bones. His bones were smashed. They broke him in the prison."

The report also revealed that Hamas used abandoned areas of a hospital in Gaza City to detain, question, and torture captives, even as other parts of the facility "continued to function as a medical centre [sic]".

Hamas used the war to "ruthlessly settle scores, carrying out a series of unlawful killings and other grave abuses," Philip Luther, Amnesty International's Middle East and North Africa director, charged. "These spine-chilling actions, some of which amount to war crimes, were designed to exact revenge and spread fear across the Gaza Strip."

"Hamas forces have displayed a disregard for the most fundamental rules of international humanitarian law," Luther added. "Torture and cruel treatment of detainees in an armed conflict is a war crime. Extrajudicial executions are also war crimes."

The report said 16 of the people killed by Hamas were already being held by the militant group when the conflict erupted and many of them were waiting to hear the verdict of their Hamas-organized trials. "Many had been sentenced after trials before courts whose proceedings are grossly unfair. A number had said they had been tortured in order to extract 'confessions,'" the report said.

Hamas violently seized Gaza from forces loyal to Abbas in 2007, leaving Palestinians bitterly divided with Hamas ruling Gaza and Abbas governing parts of the West Bank. Since then, Hamas has launched thousands of rockets at Israel and fought three wars with the Jewish state. According to official U.N. figures, over 2,200 Palestinians were killed during the 50-day war last summer. On the Israeli side, 67 soldiers and six civilians were killed.

In March, Amnesty International accused Hamas of war crimes for launching unguided rockets and mortars from civilian areas in Gaza toward civilian areas in Israel, saying that was a breach of international law. In particular, the report cited an incident in which a missile launched by Hamas misfired and killed 13 Palestinians, 11 of them children, when it exploded next to a market in a refugee camp. 

The first two reports mainly focused on the activities of the IDF and included strong criticisms of the Israeli military and accusations of "callous indifference" and "war crimes", which were again mentioned by Luther. "The fact that Palestinian armed groups appear to have carried out war crimes by firing indiscriminate rockets and mortars does not absolve the Israeli forces from their obligations under international humanitarian law,” he said.

Luther added, “The devastating impact of Israeli attacks on Palestinian civilians during the conflict is undeniable, but violations by one side in a conflict can never justify violations by their opponents.”

In reaction to the latest Amnesty International report, Salah Bardawil, a Hamas official in Gaza, told the Associated Press the incidents mentioned in the report took place 'outside the framework of the law' and Hamas was investigating them.

The Associated Press contributed to this report. 

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