[JURIST] Palestinian Hamas [GlobalSecurity backgrounder] authorities should end the systematic detention, torture, and execution of supporters of Israel and the rival Fatah party [GlobalSecurity backgrounder], according to a report [text, PDF; press release] released Monday by Human Rights Watch (HRW) [advocacy website]. HRW said the tactics had been documented since December. It said that even though Israel withdrew its forces from the Gaza strip in early 2009, Hamas has continued its practice of extraordinary internal violence in the region, leading to 14 deaths and other human rights violations since January:

Of particular concern is the widespread practice of maiming people by shooting them in the legs, which Hamas first used in June 2007, when it seized control inside Gaza from Fatah. According to the Independent Commission for Human Rights (ICHR), the human rights ombudsman organization of the Palestinian Authority, unidentified gunmen in masks deliberately inflicted bullet wounds to the legs of at least 49 people between December 28, 2008 and January 31, 2009…

…Abductions and severe beatings are another major concern. According to ICHR, unidentified perpetrators physically abused 73 Gazan men from December 28 to January 31, causing broken legs and arms. Human Rights Watch documented three such cases of Fatah supporters assaulted during and after the Israeli offensive, as well as one case of what appeared to be a politically motivated house arrest.

The group urged Hamas authorities to hold accountable those responsible for using the methods, which it said violated the Palestinian constitution [text, PDF], the UN Convention Against Torture [text], and the International Covenant on Civil and Political Rights [text]. Hamas denied that it took part in politically motivated attacks but has promised to investigate [Reuters report] any attacks aimed at Fatah.

Earlier this month, Hamas said that it would cooperate [JURIST report] with a UN Human Rights Council [official website] mission sent to the region to investigate possible war crimes that occurred during hostilities with Israel. In February, Palestinian leaders asked the International Criminal Court (ICC) [official website] to consider prosecuting Israel authorities for war crimes it had allegedly committed in the Gaza region, but the ICC said it was not sure whether it would have jurisdiction over the region [JURIST report], because it was not recognized as a state by much of the international community. In January, Israeli government authorities responded [JURIST report] to Hamas violence directed at Israel by filing two letters of complaint [text; second letter text] with UN Secretary-General Ban Ki-moon and warned militants that they would pay a "heavy price" [AP report] if attacks continued.