State prison guards, angered at the firing or suspension of 11 fellow guards in the past week for alleged inmate mistreatment, began a "work to rule" slowdown today at the Maryland prison complex near Hagerstown.

Officials of the state Department of Public Safety and Correctional Services here reported that meals for the more than 4,000 inmates were served about 20 minutes late, but said no other problems occurred.

About 700 guards are assigned to the complex, which includes the Maryland Correctional Institution and the Maryland Correctional Training Center, a few miles south of Hagerstown. Guard union representatives said virtually all the guards, working in round-the-clock shifts, are participating in the action.

A spokesman said the work-to-rule action included writing reports "with extra care, making sure everything is absolutely all right" and conducting a complete "bar check," that is, examining every security bar in every window of the prison facilities, rather than the usual random check.

The guards, members of the Maryland Classified Employees Association, mounted their protest after state Division of Correction Commissioner Jon P. Galley fired three training center guards last Friday in connection with an altercation between two inmates Aug. 24.

Galley fired an additional four guards and suspended four others Monday over the alleged beating of six inmates in October of last year.

The guards have denied the allegations, contending that state investigations failed to show any evidence of wrongdoing. Furthermore, the employes' association labor relations representative, Eric W. Prior, said today that state investigators tend to "take the word of inmates over the officers' " and leave guards little discretion in using physical force to subdue unruly inmates.

Also, he said, the state attorney general's office has refused to provide legal assistance to officers sued for civil rights violations.

The attorney general's office has said it should not provide legal representation in court because of administrative charges against the eight in the Division of Correction that are subject to review by the state personnel department.

Prior said the three guards were fired as a result of the Aug. 24 incident because they had removed three inmates from their cells without a supervisor present. He said a new regulation requires the presence of a supervisor, but noted that the regulation was not posted until Sept. 8, 15 days after the incident.

The regulation, Prior said, is designed to provide maximum supervision and ensure that at least one witness is present when an inmate is removed from a cell--a critical moment when altercations between inmates and guards can erupt.

A Division of Correction spokeswoman would not discuss the Aug. 24 incident, except to say it involved an "altercation between two inmates."