More than two-dozen state prison inmates filed a lawsuit Thursday against the Massachusetts Department of Correction, as well as individual prison officials and officers, claiming they were beaten and assaulted during a "shakedown" at a Shirley prison.

The 25 inmates filed the lawsuit in Suffolk Superior Court over the October 2000 sweep at the medium-security Massachusetts Correctional Institute at Shirley, where prison officers in riot gear searched prisoners and their cells over three days looking for weapons and contraband.

Patricia L. Garin, the inmates' attorney, said the shakedown took place with no provocation, and that nothing going on at the prison justified what she described as assaults on the prisoners.

The lawsuit, which seeks unspecified damages as well as changes to prison protocol, names Department of Correction Commissioner Michael T. Maloney; Associate Commission Ronald P. Duval; Eugene Marsolais, the head of the tactical squad that carried out the searches; corrections officers involved in the shakedown; and MCI-Shirley supervisors.

DOC spokesman Justin Latini declined to comment, saying only that a DOC probe of the shakedown that found no wrongdoing "speaks for itself."

David Vermillion, a spokesman for the Massachusetts Correction Officers Federated Union, also said the DOC investigation cleared officers.

He said the timing of the lawsuit shortly after the murder of defrocked priest John J. Geoghan in Souza-Baronowski Correctional Institute - also in Shirley - as well as the recent escape of a sexual offender, suggest that "inmates are trying to capitalize on recent public criticism of our officers."

During the three-day shakedown that started Oct. 17, 2000, more than 1,000 inmates were strip-searched, placed in restraints, removed from their cells and searched again with metal detectors.

In the lawsuit, inmates complained they were beaten, punched and dragged, attacked by dogs, and called racial slurs. Many complained that their possessions were destroyed in the shakedown, including a blind inmate who alleged that his cell was turned upside down and his head bashed into a wall.

After complaints of assaults from inmates, a DOC investigation, which included interviews with 43 prisoners and about 100 members of the department's tactical team, ended with no finding of abuse or wrongdoing at the prison.