The flag of the Syrian al-Qaeda-affiliated group Islamic State of Iraq and Greater Syria. Photo: Wikimedia Commons.

An Islamic State (ISIS) affiliate accused Hamas of destroying one of its mosques in the Gaza Strip on Sunday, the Jerusalem Post reports.

And on Monday, an ISIS-affiliated organization reportedly detonated an explosive device near Hamas’ security headquarters used to train police recruits.

These developments indicate rising tensions exist between Hamas and groups affiliated with the Islamic State in Gaza. Before Monday’s bombing, the ISIS affiliate threatened various Hamas security officers, publishing some of their names and photos, after Hamas arrested several Salafist jihadi supporters. The ISIS affiliate called on “all of our soldiers” to act against Hamas if the Salafist prisoners were not released.

“Hamas and its security forces have 72 hours from the release of this statement to free all Salafist (jihadist) prisoners…all options are open to us to respond to Hamas,” read the statement.

Ansar al-Dawleh al-Islamiyeh (Supporters of the Islamic State) claims that Hamas used three bulldozersSunday to demolish the mosque in Deir Al-Balah. Hamas did not remove copies of the Quran before destroying the mosque, the Jerusalem Post‘s Khaled Abu Toameh reported on Twitter.

“…in light of Hamas’ latest action, we renew our allegiance to Abu Bakr Al-Baghdadi and call on him to strengthen his influence, to open up a war in Palestine in order to unite together in a war against the Jews and their accomplices,” a statement from the ISIS affiliate said.

Hamas did not publicly comment on the accusations; however, sources close to the terrorist organization said that the bulldozed building was a Salafi-jihadist office and not a mosque.

The ISIS group accused Hamas of acting worse than the “Jewish occupiers,” according to Israel NRG and reported by Algeimeiner.

“Armed men from Hamas came to Deir Al-Balah and destroyed the mosque, acting in a way that even the Jewish occupiers and the Americans have not acted,” the ISIS group tweeted.

Steven Emerson is the Executive Director the Investigative Project on Terrorism (www.investigativeproject.org) where this article first appeared.