GAZA — The Islamic group Hamas that controls Gaza executed three Palestinians on Saturday, one who was convicted of collaborating with Israel and two others who had been found guilty of murder, according to a statement from the Hamas Interior Ministry.

The statement said the three men were hanged at a security site in Gaza City. It did not give any details about their identities.

The last executions of Palestinians convicted of collaboration with Israel took place in July, when a father and son were put to death after being found guilty of providing information that helped Israel kill a Hamas leader in 2004.

Of the 11 Palestinians executed in Gaza since Hamas took over, most were convicted of spying for Israel.

Hamas won Palestinian parliamentary elections in 2006 and then seized full control of Gaza a year later after a brief but bloody factional war. Hamas defeated the rival Fatah forces loyal to the Palestinian Authority president, Mahmoud Abbas, confining Mr. Abbas’s influence to the West Bank.

Amnesty International issued an urgent statement on Thursday saying that four men were on death row in Gaza and could be executed at any time because their appeals had been rejected. The three men executed Saturday are presumed to have been part of that group.

Palestinian law allows for the death penalty for people convicted of collaboration with Israel, murder or drug trafficking. Execution orders are supposed to be approved by the president of the Palestinian Authority, but Hamas does not recognize Mr. Abbas’s presidency and did not seek his approval.

The Gaza-based Palestinian Center for Human Rights said that the approval of death sentences was the “exclusive right” of the Palestinian Authority president, and that carrying out any execution without the president’s approval was “against the law and the Constitution.”

The Hamas interior minister, Fathi Hamad, said Saturday that the death penalty was meant to deter all those who would “betray their homeland.”

He was speaking at a graduation ceremony of security officers in Gaza, according to a Web site affiliated with Hamas.