Palestinians from the Gaza Strip and the West Bank have joined the ranks of the Islamic State group, Channel 2 reported Thursday, citing intelligence sources.

The report came a day after Defense Minister Moshe Ya’alon formally designated the organization a terror group, along with Al-Qaeda affiliate Abdallah Azzam Brigades.

That move enables Israel to act against the organizations by prohibiting gatherings, recruitment, fundraising and other activities, Israel Radio reported.

The step was taken upon the recommendation of the Shin Bet, possibly to grant the organization legal tools to deal with Palestinian jihadis who might return from fighting in the group’s ranks in Syria and Iraq.

On Wednesday night, Israel’s Channel 10 aired footage of what it said was an Islamic State rally on the Temple Mount. The report, which is to be broadcast in full next week, said the gathering underlined that the Islamic State intends to focus on Israel in the future.

The gathering, attended by thousands, was organized by the Tahrir party, which the report described as being the “Palestine branch” of Islamic State.

Speakers were filmed declaring their anticipation of the “liberation” of Jerusalem and decrying Jewish “pollution” of the city. Several black IS flags were seen in the footage.

The footage was filmed on a recent Friday, the report said.

The Islamic State group has swept through northern and western Iraq from its stronghold in neighboring Syria. It follows an ultra-conservative, violent interpretation of Islam and is accused by rights groups and the United Nations of committing war crimes, including the mass killings of soldiers, Shiite Muslims and followers of the ancient Yazidi faith in Iraq.

On Tuesday, the group released a video that showed an Islamic State fighter beheading captive US-Israeli journalist Steven Sotloff.

To halt its spread, the US has conducted airstrikes in northern Iraq and shipped new weapons to Lebanon’s military, including automatic rifles, mortars and anti-tank weapons.

Lazar Berman and AP contributed to this report.