JERUSALEM — Nine Israeli soldiers were due to appear before a military court for an initial hearing Tuesday over what a defense lawyer said were allegations of sexual abuse of a Palestinian at a facility where Israel has held prisoners from Gaza during the war.

The investigation has stoked tensions between the military command and nationalists in Prime Minister Netanyahu’s government who advocate a tough approach by Israel in the 10-month-old war in Gaza.

The soldiers’ detention Monday triggered protests by supporters demanding their release, including members of parliament and at least two government ministers. 

On Monday, several hundred protesters broke into the facility in southern Israel, known as Sde Teiman — Hebrew for Yemen Field — and then later into the military base where the soldiers were being held. Video showed them scuffling with troops before being forced out.

Defense lawyer Nati Rom, who is representing three of the soldiers, did not elaborate on the nature of the alleged sexual abuse and said they were innocent. 

The military has given no details on the investigation, saying only it was looking into allegations of “substantial abuse.” Beyond the alleged abuse now being investigated, Israeli authorities have generally denied abuses in detention facilities for Palestinians.

The military court hearing Tuesday afternoon at the Beit Lid base in central Israel was expected to rule on whether to extend the soldiers’ detention, raising the possibility of new protests.

In a signal of how the case has roiled Israeli politics, the defense minister, Yoav Gallant, who denounced the protester break-ins at the sites, demanded an investigation into whether the national security minister, Itamar Ben-Gvir, had “prevented or delayed the police response” to the riots.

Mr. Gallant said the lack of police presence forced the military to divert forces to the bases to expel the protesters. In a letter to Mr. Netanyahu, he called on him to “act harshly against the coalition members who participated in the riots.”

Mr. Ben-Gvir, whose ministry is in charge of police, responded with his own letter to Mr. Netanyahu saying the allegations he delayed police response to the riots were baseless.

On Monday, Mr. Ben-Gvir denounced the soldiers’ detention as “shameful” and called them “our best heroes.” Referring to conditions at detention facilities, he said “the summer camps and patience for the terrorists are over.”

The defense lawyer, Mr. Rom, said the incident under investigation took place at Sde Teiman a month ago. He said the detainee attacked officers during a search, and the soldiers “used force but didn’t do anything sexual.” He said the detainee was a high-ranking member of Hamas.

His account of the incident or the detainee’s identity could not be independently confirmed. Mr. Rom works for Honenu, a legal group that specializes in defending Israeli soldiers and civilians facing prosecution over incidents of violence with Palestinians.

Israel’s military chief, Lieutenant General Herzi Halevi, condemned the protesters’ break-ins and said he fully supports the military prosecutors’ investigation. “It is precisely these investigations that protect our soldiers in Israel and the world and preserve the values” of the military, he said.