The Gaza Strip's Islamist rulers Hamas on Wednesday hanged a prisoner who had been convicted of murder, its interior ministry said, despite international calls for a halt to executions.
Hamas last carried out the death penalty for a criminal offence in July 2012, normally reserving the sentence for "collaborators".
"At 4:30 pm (1430 GMT) on October 2, the death penalty was carried out against Hani Mohammed Abu Aliyan from Khan Yunis for his crime of killing Hazem Hassan Barham," the ministry said in a statement.
The Palestinian territory's appeals court had rejected challenges against the sentence, the ministry said.
Human rights groups have repeatedly urged Hamas to halt executions, including that of Abu Aliyan, which was initially to be carried out after the Muslim Eid al-Fitr holiday in August.
Amnesty International on Wednesday reiterated its call ahead of the hanging.
"The authorities in Gaza must urgently stop the execution scheduled for today," the London-based watchdog's Middle East director Philip Luther said.
"It is deeply disappointing that the Hamas de facto administration is returning to using the gallows after a brief reprieve in the summer."
Hamas on June 22 hanged two men accused of collaborating with Israel.
But Wednesday's hanging was the first time since July 2012 that the Islamist group has implemented capital punishment for murder, when it executed three Gazans.
Under Palestinian law, collaboration with Israel, murder and drug trafficking are all punishable by death.
The latest execution was carried out in front of "concerned parties" and "the elite of Palestinian society," Hamas said, without giving further details.
A second interior ministry statement said Abu Aliyan had committed two murders -- that of Barham and of an unnamed child -- but did not specify if he had been sentenced for the second murder.
Abu Aliyan killed a six-year-old identified by the initials "MA" in 2000 "by striking the child on the head with a sharp instrument... and then beating his head with a large rock" after he had lost consciousness, it said.
He killed Barham, whom he knew, in 2009 by stabbing him to death over a quarrel about a financial loan, the statement said.
According to previous reports by Amnesty, 27-year-old Abu Aliyan confessed under torture to the rape and murder of the six-year-old boy.