A bomb blast targeted Hamas’s security headquarters in Gaza City on Monday, witnesses said, after Islamists issued a threatening message calling for the release of prisoners.

The explosion just before dawn damaged the building’s perimeter wall, witnesses told AFP.

The security forces, run by de facto Gaza ruler Hamas, were not immediately available for comment.

An online statement just hours before the blast, apparently issued by a radical anti-Hamas group, threatened to “act against chosen targets” if militant prisoners were not freed within 72 hours.

It was unclear if the statement and the explosion were linked, however Islamists in Gaza have issued similar threats in the past.

“Hamas and its security forces have 72 hours from the release of this statement to free all Salafist (militant) prisoners,” said the statement from a group calling itself the Supporters of the Islamic State in Jerusalem.

“Our soldiers are ready to act against chosen targets at the end of this ultimatum,” it said.

A string of explosions have hit Gaza in recent months, the majority however involving attacks on the property of Fatah officials in the Hamas-dominated region.

A Salafist group based in the Gaza Strip accused Hamas Saturday of torturing its supporters in prison and closely watching other supporters in cities and refugee camps across the coastal enclave.

The group urged any of their supporters that suffer assault to document it and send details to the group’s leadership.

Hamas has reportedly targeted a more violent Salafi fringe in particular, which it views as a threat to its power in the same vein as extremist groups such as the Islamic State group.

Hamas security forces arrested a Salafist leader last month, alleging that he was a supporter of the Islamic State group (IS) that holds vast swathes of territory in Syria and Iraq.

Gazan militants have pledged allegiance to IS in the past, but there has been no confirmation from the group itself that it has a presence in Gaza.

The majority of Palestinians in both the West Bank and Gaza Strip reportedly reject IS, according to a March 2015 poll conducted by the Palestinian Center for Policy and Survey Research.

86 percent of those polled believed IS to be a “radical group that does not represent true Islam.”

A blast in Gaza City was also reported Monday by Palestinian media, however it is not clear from reports if the device, which exploded in the Sheikh Radwan neighborhood, was a separate incident.

No injuries were reported from either blast.

(Agencies and Ma’an – www.maannews.net)