Gaza's Hamas government on Tuesday executed a Palestinian father and son convicted of spying for Israel in defiance of President Mahmoud Abbas, who by law has final say in implementing such rulings.

Hamas officials said the men had confessed to providing Israeli forces with intelligence that helped them track down Palestinians including the group's chief Abdel-Aziz al-Rantissi, who was killed in a 2004 air strike on his car.

Open gallery view Hamas policemen marching along a street in Gaza City on July 26, 2011. Credit: AFP

The convicts had lost a court appeal against their sentence.

The Islamist Hamas has controlled the Gaza Strip since driving out Abbas's secular Fatah faction in a 2007 civil war.

The rival movements signed a reconciliation accord in Cairo in May but its implementation has been held up by disputes over the format of the proposed Palestinian power-sharing government.

Human rights groups have criticized Hamas executions, which are permitted under Palestinian law but require Abbas' approval.

The U.S.-backed leader has withheld this, creating de facto moratorium on capital punishment in the Israeli-occupied West Bank, where his administration still holds sway.

Three Gazans were put to death by Hamas authorities this year and five in 2010, most for espionage and by firing squad.

After Tuesday's executions, relatives of the condemned burned tires in protest on a central Gaza street before being dispersed by police.

