In a major shake-up at the New York City Correction Department, three high-ranking officials, including the top uniformed officer, are stepping down amid mounting criticism over the handling of violence and corruption at Rikers Island.

The chief of department, William Clemons, and two deputies — Joandrea Davis, the bureau chief of administration, and Gregory McLaughlin, the bureau chief of facility operations — are departing, correction officials said. The surprise departures came just five months after all three were appointed to their current posts by Mayor Bill de Blasio’s correction commissioner, Joseph Ponte.

A department spokesman said the changes were the result of “a restructuring” by Mr. Ponte in an effort to halt brutality on the most violent cellblocks.

The department has been under intense pressure from lawmakers and federal and city investigators to address systemic brutality and corruption at Rikers, the country’s second-largest jail complex. The United States attorney’s office for the Southern District of New York, which in August released a damning report detailing abuse of adolescent inmates at Rikers, has threatened to sue the city if changes are not made.