The Department of Corrections announced Thursday that the incarcerated men believed to be responsible for an attack that injured five correctional officers have been transferred to another facility.

In the attack at the Souza Baranowski Correctional Center, a maximum security prison in Lancaster, two police officers suffered stab wounds and three others who responded to the incident were injured. One of the officers was stabbed 12 times in the back and suffered a punctured lung, according to the Massachusetts Correction Officers Federated Union.

All five officers were taken to a hospital and four have since been released, the department said in a statement. The fifth officer remains hospitalized in serious but stable condition with non-life-threatening injuries.

Following the attack, the department “modified” procedures at the prison to “ensure the safety of all persons working and living there.”

Shawn Jenkins, the department’s interim commissioner, pledged to conduct a “thorough security assessment and review of protocols” to ensure the safety of all those who live and work in the department’s facilities.

The safety of correctional officers is the agency’s top priority, he added.

“My thoughts are with the officers and their families during this time, and the Department offers the officers our full support as they recover from their injuries,” Jenkins said in the statement. “Violence against DOC employees is unacceptable, and we will take the necessary steps to ensure those responsible are held legally accountable.”

Dennis Martin, the union’s president, said concerns about conditions at the prison had “fallen on deaf ears.”

“The department has a lot of resources to … ensure the safety of this prison for staff and inmates,” he said during a news conference outside the maximum security prison. “It’s very disheartening how they have responded to this situation.”