The Islamic State's (Isis) arm active in Egypt's Sinai peninsula has issued a threat against Hamas, the powerful organisation controlling the Gaza Strip, with a brutal execution video. As their long-running conflict erupted into the open, the Sunni extremist group said it is declaring war on Hamas and vowed it will be removed from the region.

Hamas has remained an influential entity in Gaza for decades. The Isis said Hamas has failed to stop President Donald Trump's Jerusalem move and needs to be overthrown.

According to the US-based monitoring agency, Site, which keeps track of jihadi platforms, the 22-minute video shows a man, identified as Abu Kazem al-Maqdisi, urging Islamic followers to mount attacks on Hamas positions in Gaza.

Maqdisi, who hails from Gaza and is now an Isis preacher in Sinai, said in the footage: "[Hamas] uses its smuggled weapons to empower that which was not revealed by God. It also fights supporters of the Islamic State in Gaza and the Sinai and prevents the migration of these supporters from Gaza to the Sinai."

Isis' latest outreach is bound to raise grave concerns as its Egyptian faction is rapidly expanding its presence from the lawless northern parts of Egypt. "Never surrender to them. Use explosives, pistols, and bombs. Attack their courts and their security locations, for these are the pillars of tyranny that prop up its throne," the knife-wielding Isis man is seen saying in the video.

Towards the end of the recording, the narrator declares a man named Musa Abu Zamat as a Hamas collaborator who allegedly smuggled weapons for them. Zamat is then shot in the back of his head at point-blank range by one of the Islamists holding a pistol.

Trump's announcement recognising Jerusalem as the Israeli capital is also displayed in the video, which criticises Hamas for cracking down on fellow Islamist organisations in the region.

Friction between Hamas and the Isis has been ongoing for nearly a year with both groups trying to strengthen their foothold.

Still, the pro-Palestine group has dismissed the latest Isis threat as one masterminded by Israel. Hamas' spokesperson Salah Bardawil wrote on Twitter that the video is "a Zionist production in which Arab tools participate to distort the resistance...This is what the Zionist intelligence agency and its lackeys have been striving for".

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Hamas supporters take part in a rally marking the 30th anniversary of the group's founding, in the West Bank city of Nablus Abed Omar Qusini/Reuters