Hamas security forces killed an activist of a rival Islamist militant group in a shoot-out at his Gaza home on Tuesday, witnesses said.

A spokesman for the Hamas-run Interior Ministry identified the man, Younis al-Honnor, as a "lawbreaker", saying he had stockpiled munitions and was shot dead after firing at security officers who came to arrest him.

Local residents who witnessed the incident said Honnor was an activist with a Salafist group. He was buried in the black flag with a religious inscription that is the standard of Islamic State insurgents who have swept other parts of the Middle East.

Hamas, the Gaza Strip's dominant faction, has mounted occasional crackdowns on more radical groups that chafe at its authority and support global holy war endorsed by ISIS and al Qaeda.

While sharing their hostility to Israel, Hamas has entered truces with the enemy state and reconciled with the U.S.-backed administration of Palestinian President Mahmoud Abbas.

"(Honnor) had booby-trapped the house he was in. Explosive belts, explosive devices and rifle-propelled grenades were found inside," the Interior Ministry spokesman said.

A statement posted on a pro-Salafist website disputed the ministry's account. "The Hamas leadership bears responsibility for this deplorable crime," the statement said.

The Gaza-based Palestinian Centre for Human Rights questioned whether Hamas forces were justified in killing Honnor and urged a public investigation.

Last Update: Wednesday, 20 May 2020 KSA 09:46 - GMT 06:46