New Jersey prosecutors have filed charges against a correctional officer and two sergeants who oversaw a cell extraction at a women’s prison that allegedly turned into a series of violent assaults, leaving inmates with injuries including a concussion and an orbital wall fracture.

New Jersey Attorney General Gurbir Grewal, who announced the charges at a news conference Thursday, said an investigation was ongoing. He added that more charges are expected in connection with the Jan. 11 incident at Edna Mahan Correctional Facility for Women, New Jersey’s only women’s prison, which houses about 700 people and has been plagued by reports of abuse. A scathing report released last year by the U.S. Department of Justice found the New Jersey Department of Corrections as a whole “fails to keep prisoners at Edna Mahan safe from sexual abuse by staff.”

According to Grewal, six women at the prison in Hunterdon County reported injuries in the January incident, which involved more than two dozen officers.

“They deployed pepper spray, rushed into the inmates’ cell, and beat several of the victims without justification,” Grewal said. He said one woman was beaten while handcuffed. Another was punched 28 times as she huddled against a wall, trying to shield her face with her arms.

Then, he said, the officials tried to cover it up.

Sgts. Amir Bethea and Anthony Valvano, two officials who led extraction teams, are charged with official misconduct, which carries a minimum five-year sentence, and tampering with public records. Officer Luis Garcia faces those same charges, along with aggravated assault.

Contacted by a reporter, Valvano hung up without commenting. Bethea and Garcia could not be reached on Thursday.

Grewal said the assaults were caught on video, which will be released once the investigation is complete. The incident was first reported by NJ.com, which said that one woman was wheelchair-bound after the attack and that dozens of staff were suspended.

William Sullivan, president of Policemen’s Benevolent Association Local 105, which represents correctional officers in New Jersey, said he was still determining whether the union would be representing the officers.

“While a review of the allegations lodged against the officers are disturbing, P.B.A. 105 fully supports a thorough investigation being conducted regarding the incidents at issue before any judgments are made,” Sullivan said in a statement.

Meanwhile, advocates said the allegations highlight the need for immediate reforms. The ACLU of New Jersey urged the state to “invest in meaningful and robust corrections oversight,” by strengthening the Office of the Corrections Ombudsperson, among other steps.

Gov. Phil Murphy, who has called the incident “horrific,” “sickening,” and “abhorrent,” released a statement Thursday pledging that the charges will be accompanied by “a full accounting of how this incident was able to happen, so that we can put in place necessary reforms and safeguards.” He has charged former State Comptroller Matt Boxer with leading that investigation.

The New Jersey Assembly Judiciary Committee will hold its own investigatory hearings, Speaker Craig Coughlin said in January. “We need answers and we need reform,” he said.

“There’s a long and ugly history at Edna Mahan,” Grewal said. “We’re using all of our tools to hold accountable those that engage in this conduct.”