Hamas is moving rapidly to reassert armed control over areas of Gaza as they are vacated by Israeli forces under the peace agreement brokered by President Trump, a report says.

The action, coming days before the terrorist group is expected to release some 20 Israeli hostages and the bodies of 28 more, flies in the face of major provisions in Mr. Trump’s 20-point peace plan, most of which has not been formally accepted by Hamas.

An Istanbul-based correspondent for the BBC quotes local sources saying Hamas has recalled about 7,000 members of its security forces and appointed five new governors, some of whom previously commanded brigades in its armed wing.

In a chilling message delivered to its security members on cell phones and text messages, Hamas said: “We declare a general mobilization in response to the call of national and religious duty, to cleanse Gaza of outlaws and collaborators with Israel,” according to the BBC.

“You must report within 24 hours to your designated locations using your official codes.”

The mobilization appears designed to take advantage of the power vacuum left by the withdrawal of Israel Defense Forces, who began pulling out of urban areas on Friday under the terms of the Trump-brokered ceasefire and now control a little more than half the territory.

A Hamas official abroad declined to comment directly to the BBC about reports that some Hamas militants have already deployed, wearing civilian clothes or the blue uniforms of the Gaza police.

But, the official said, “We cannot leave Gaza at the mercy of thieves and militias backed by the Israeli occupation. Our weapons are legitimate, they exist to resist occupation and they will remain as long as the occupation continues.”

The ominous report stands in stark contrast to the past days’ scenes of jubilation in Israel, where family and supporters of the hostages have been celebrating the imminent return of their loved ones, and of weary but joyful Palestinians trekking back to their homes in the largely ruined enclave.

It also exposes a major shortcoming in the ceasefire agreement brokered by Mr. Trump’s envoys Steve Witkoff and Jared Kushner, in which Hamas agreed to release all remaining hostages but did not address requirements that it lay down its weapons and forsake any role in the future leadership of Gaza.

In Qatar, a senior Hamas official rejected any notion of Hamas members moving into exile and told Agence France-Presse that future talks on that and other elements of the plan will involve “many complexities and difficulties.”

“Talk about expelling Palestinians, whether they’re Hamas members or not, from their land is absurd and nonsense,” political bureau member Hossam Badran said in an interview.

An armed Hamas resurgence would confirm the fears of many Israelis who have been skeptical of the deal, and could complicate plans for a triumphant visit to Israel by Mr. Trump, who is scheduled to arrive in the country Monday morning. All the remaining hostages, living and dead, are due to be returned to Israel later that day.

About 200 U.S. troops are already in Israel to monitor the ceasefire, according to AP. The agency said they will set up a center to facilitate the flow of humanitarian aid as well as logistical and security assistance.

Messrs Witkoff and Kushner met with senior U.S. and Israeli military officials in Gaza on Saturday, according to the Associated Press, but have not commented publicly on the BBC report.

The two appeared along with Mr. Trump’s daughter, Ivanka, at a Saturday evening rally in Tel Aviv’s Hostage Square, where the crowd cheered at references to Mr. Trump and the IDF but booed when Mr. Witkoff mentioned the contributions of Prime Minister Benjamin Netanyahu.

Ms. Trump told the crowd that the return of each hostage is a “triumph of faith, of courage and of our shared humanity,” adding that she hopes that the “next chapter” in the Israel-Palestinian saga will be a “lasting and enduring peace.”