Jerusalem (CNN) -- Gaza's ruling Hamas government said Tuesday it executed two Palestinian men for collaborating with Israel.
The father and son, ages 58 and 29, were convicted by a Gaza court in 2004 of assisting the enemy and providing information used to assassinate Palestinians.
"The issue of collaborators is highly dangerous in the Palestinian society," Ihab Elghosen, a spokesman for Hamas' Interior Ministry, told CNN. "We must act forcefully because there is a war underneath the surface between us and the Israeli intelligence and we must win it."
Palestinian law requires death sentences to be ratified by the president. Elghosen said the move was authorized by the Hamas government, but officials in Ramallah called the decision "illegal."
Palestinian Deputy Interior Minister Hassan Alawi told CNN "any decision of this kind has to be signed by the president. Of course, because of the situation between Fatah and Hamas, there was no ratification and it is therefore illegal. To my regret, in the current situation there are many wrongdoings. We would expect our brothers in Gaza to be more tolerant, especially when it comes to human lives because they are irreversible. You cannot revive the dead if there is a mistake."
According to the Al Mezan Center for Human Rights, the families of the men received a call at 1 a.m. Tuesday, asking them to visit their relatives. The meeting took place until 3 a.m., and at 6 a.m. the men's bodies were received at Gaza's Al-Shifa hospital.
"It appears from the state of the bodies that the men were hanged," a statement from Al Mezan says. The center noted the danger in collaborating with Israel, but said that "(while) it is important to bring them to justice, we strongly object to the use of the death penalty and see the move by Hamas as illegal."
Hamas seized power from the Palestinian Authority in Gaza in 2007.
In a report released in 2010, human rights group Amnesty International's Middle East program director Malcolm Smart said legal proceedings that led to death sentences "failed to meet international fair trial standards" and made any resulting executions "especially abhorrent."
CNN's Talal Abu Rahma and journalist Marwah Jbara-tibi contributed to this report