Maryland State Police are investigating a melee that erupted Saturday night at the Brockbridge prerelease complex in Jessup following a power failure. Fifteen inmates were injured.

Police and prison officials said the violence did not appear to be linked to the indictment last week of 27 Brockbridge inmates for allegedly committing crimes ranging from robbery to murder while free on prerelease programs.

The arrests led prison officials to halt all work and begin a study of release programs at Brockbridge. About 200 of the center's 800 inmates were affected by the suspension.

No violence was reported Saturday night at the nearby House of Correction and Maryland Correctional Institution for Women, which also were affected by the power failure. The blackout began when a tree fell on transmission lines about two miles away, prison officials said.

Fighting broke out spontaneously when the second of the failures darkened the minimum security prison at about 9 p.m., officials said. "When the lights go out you have the opportunity to get even with someone you don't like," a State Police spokesman commented.

Using fists and illicit weapons, inmates battled each other in dormitories and a second-floor corridor in the Brockbridge Correctional Facility, a minimum security prison in the prerelease complex, said Michael Menefee, assistant superintendent.

Guards equipped with flashlights moved among the prisoners attempting to restore order. No guards were reported hurt.

Nine of the injured inmates were taken to a clinic at the House of Correction. Six others -- including the most serious injuries, a man with a foot injury and another struck on the head with a blunt instrument -- were taken to Baltimore for treatment. All had been returned to the prison by yesterday.

Ten State Police troopers were sent as a precaution but guards broke up the fighting. Two State Police investigations that could lead to criminal prosecutions of inmates involved in the fighting.

State Police also are continuing a probe begun on Feb. 10 when a prisoner free on work-release allegedly killed another inmate in downtown Baltimore.