Human rights activists urged Gaza's Hamas rulers Thursday not to execute Palestinians who spied for Israel, as Hamas officials prepared to resume executions following a decade-long lull.

Eleven men are on death row in Gaza, six convicted by Hamas courts of murder and five of spying for Israel, said the Gaza-based Independent Commission for Human Rights. Six others have been sentenced to death in absentia.

Palestinian law allows the death penalty for those convicted of collaborating with Israel and other offenses. Courts in Gaza and in the West Bank — ruled by Hamas' rival, Palestinian President Mahmoud Abbas — have handed down death sentences over the years.

But Abbas has not signed execution orders since taking office in 2005, and no officially sanctioned executions have taken place in Gaza since 2000.

Hamas declarations about resuming executions were seen as a move to assert internal control and assert the Islamic militant group's independence from the Western-backed Abbas.

After three years of a crippling blockade of Gaza's borders and a devastating Israeli offensive more than a year ago, Hamas has little to offer Gazans other than a promise of maintaining internal security.

Bill Van Esveld of the New York-based Human Rights Watch said that in executing prisoners, Hamas "would be making not just a backward step, but an unprecedented retrograde step."

Hamas Interior Minister Fathi Hamad first mentioned in a radio interview last month that Hamas intends to execute spies.

His spokesman, Ehab Ghussein, told The Associated Press the executions would deter others.

"If they don't see that some people are getting executed according to the law, they will continue collaborating with the Israelis," he said, adding that executions would likely begin "in a few months."

Hamas would risk deepening its international isolation if it carries out executions.

Amnesty International and other human rights organizations accused Hamas gunmen of killing suspected collaborators during the chaos surrounding Israel's Gaza offensive in the winter of 2008-2009.

After the war, a report from the Palestinian Center for Human Rights said 17 people were found dead after fleeing a Gaza prison damaged in an Israeli airstrike. Most had been held as suspected collaborators, the report said.

Hamas seized Gaza from forces loyal to Abbas in 2007, leaving him with only the West Bank. The rivals have followed separate tracks, maintaining separate governments and security forces.

This week, Hamas Attorney General Mohammed Abed argued that the group could carry out executions without Abbas' approval.

In the West Bank, Palestinian Authority spokesman Ghassan Khatib said Thursday that any executions carried out by Hamas would be considered illegal. "The whole process is illegal and illegitimate, and consequently the outcome of these so-called courts is not legal," he said.