Palestinian and Israeli human rights groups have denounced Thursday's executions of two collaborators in Gaza.

The Palestinian Centre for Human Rights reiterated in a statement its position rejecting the death penalty, which it called "a grave and unjustified violation of the right to life and a form of torture and cruel and inhumane treatment."

The Ministry of the Interior in Gaza executed by firing squad Nasser Salama Abu Fraih, 35, from Jabaliya and Mohammed Ibrahim Isma'il (As-Sabe), 36, from Rafah.

These death sentences were carried out without the ratification of the president, which is required under Palestinian law and constitutes a violation of the law and constitution, the PCHR added.

However, the group reiterated its position that the PA has a duty to prosecute those accused of collaboration with Israel.

"Abolishment of the death penalty does no mean being tolerant of criminals; however, an appropriate deterrent penalty which complies with international law and maintains our humanity, should be considered," the statement said.

The Israeli human rights group B'Tselem, meanwhile, strongly condemned the executions

"The death penalty is immoral and violates the basic right to life of every human being. B'Tselem holds that under no circumstance must it be imposed," the Israeli human rights group said in a separate statement.

In addition to objection in principle to the death penalty, B'Tselem said the execution was based on a trial that did not meet even minimal standards of due process. Gazans charged with collaboration are unable to mount a proper defense or to appeal the verdicts and punishments imposed upon them, according to the group.

Thursday's executions were the first official executions in Gaza since Hamas' takeover in 2007.

According to Human Rights Watch, during Israel's Operation Cast Lead, 32 Palestinians were executed without trial by Palestinian armed groups apparently associated with Hamas, for allegedly providing Israel with information.

Last week, the General Prosecution Office in Gaza said that ratification of outstanding death sentences was not only necessary but that it was a legal duty. In a public statement issued on 25 March, Gaza Attorney General Mohammed Abed announced that during the previous two months, his office began processing the death sentences of those convicted of collaboration and murder.

Two days earlier, Gaza Interior Minister Fathi Hammad said in a radio interview that his ministry had decided to execute prisoners convicted of collaboration despite the objections of local human rights organizations.

In May 2009, Hamas announced that it was establishing a committee composed of legal advisors and officials in the de facto Ministry of Justice who would be responsible for ratifying death sentences in Gaza. The General Prosecution Office announced Sunday that the cabinet had a duty to help ratify death sentences in order to implement outstanding death sentences.

The last known executions in Gaza were carried out in June and July 2005, prior to the establishment of the de facto government in Gaza.