As state lawmakers on Thursday questioned whether Maryland should replace its oldest and most troubled corrections facility, the union representing officers at Maryland’s newest prison warned that conditions there may be even worse now.

A surge of attacks on corrections officers by inmates at the maximum security North Branch Correctional Institution in Western Maryland has left 12 officers injured since June 28, state corrections officials said.

Several assaults appear to be gang-related, according to the union, and the 1,400-inmate facility has been placed on lockdown until at least early next week while investigators gather evidence to pursue charges against several inmates.

Patrick Moran, president of the American Federation of State, County and Municipal Employees in Maryland, the union for state corrections officers, said its members believe that the state has not done enough to keep officers safe.

Moran said that in the hours before the most recent assault, when two officers were wounded July 23, corrections officers were warned before their shifts that information gleaned from a recorded jail phone call suggested another attack was imminent, union officials said. State officials did not immediately comment on that account.

More Post coverage of the Maryland jail scandal.

“What did they do with that information? Nothing,” Moran said. “People are losing faith in management’s ability to create a safe environment. This is poor oversight, poor management.”

Rick Binetti, spokesman for the Department of Public Safety and Correctional Services, said officials are “very sensitive to the safety concerns of staff and inmates” and noted that serious assaults dropped between 2007 and 2012. He said that none of the guards was seriously injured and that staff needed to call 911 in only one instance.

Binetti, who said the facility houses some of the state’s most violent inmates, added that the department is reviewing its evaluation of inmates and staffing assignments.

The department has been under siege since a recent federal indictment detailed widespread collusion between gang members and guards at the state-run Baltimore City Detention Center. Officers smuggled cellphones, drugs, money and other contraband for members of the Black Guerrilla Family.

The detention center is the oldest in Maryland, dating to the Civil War. North Branch, by contrast, in Cresaptown, began receiving inmates in 2003 and has state-of-the-art technology.

Moran, who voiced his complaints Thursday in a meeting with Corrections Secretary Gary D. Maynard, said he thinks he knows at least part of the reason there have been so many recent attacks.

“Intelligence gathering in the prison has become a banker’s hours — 9 to 5, and no weekends,” Moran said. He said the union demanded that the state devote more resources to intelligence gathering.

In the most recent incident, Binetti said, two officers were assaulted by inmates in the dining hall. In some other instances, he said, inmates attacked officers who were attempting to conduct a search.

Moran said some of the officers who have been hurt suffered “quite serious injuries and are still in care” and others have been treated and released.

“But that’s really irrelevant,” Moran said. “This shouldn’t be happening.”