Islamic State (ISIS) insurgents on Tuesday threatened to topple Hamas in Gaza, accusing the group of being “insufficiently stringent” about religious enforcement, according to Reuters.

The video statement, issued from an ISIS stronghold in Syria, was a rare public challenge to Hamas, which has been cracking down on jihadists who oppose its truces with Israel and reconciliation with longtime rival Fatah.

"We will uproot the state of the Jews (Israel) and you and Fatah, and all of the secularists are nothing and you will be over-run by our creeping multitudes," said a masked ISIS member, according to Reuters, in the message addressed to the "tyrants of Hamas".

"The rule of Sharia (Islamic law) will be implemented in Gaza, in spite of you,” the jihadist continued.

“We swear that what is happening in the Levant today, and in particular the Yarmouk camp, will happen in Gaza," he said, referring to ISIS advances in Syria, including the Damascus district inhabited by “Palestinian refugees.”

This not the first time that ISIS has threatened Hamas. In May, after Hamas demolished a mosque used by members an ISIS-affiliated Salafist organization, ISIS called Hamas "worse than the Jewish and American occupiers" and gave it 72 hours to release its detained members.

An ISIS-affiliate in the Sinai Peninsula later claimed it launched two "bombs" - reportedly 82 mm mortar shells - at Hamas posts in Gaza.

And last week, a group calling itself “ISIS Palestine” put up fliers around eastern Jerusalem threatening Christians in the area with "revenge".

ISIS does not have an operational presence in Israel, but support for the group among Islamists is on the rise, with dozens of Arab citizens leaving for Syria and Iraq to fight for the jihadist organization after ISIS members took part in Hamas's terror war against Israel last summer.

Meanwhile, Intelligence Minister Yisrael Katz accused Hamas on Tuesday of partnering with ISIS affiliates in the Egyptian Sinai - a charge long denied by Hamas.

"There is cooperation between them in the realm of weapons smuggling and terrorist attacks. The Egyptians know this, and the Saudis," Katz told a Tel Aviv conference organized by the Israel Defense journal.

"At the same time, within Gaza, ISIS has been flouting Hamas. But they have common cause against the Jews, in Israel or abroad," he added.