RCMP have laid charges against three men in connection with a deadly riot at the Saskatchewan Penitentiary a year and a half ago.

The three, 27-year-old Kelfert Wayne Watetch, 23-year-old Brandon Wyatt Burns and 21-year-old Landon Bryce McKay, are accused of second-degree murder and attempted murder, according to police.

About 200 inmates were involved in the riot, which occurred in December 2016 and led to a lockdown at the Prince Albert prison. Inmate Jason Leonard Bird, who was 43, was found unresponsive in the medium-security unit and pronounced dead in hospital. Another inmate, a 31-year-old, was also injured in the attack.

RCMP said in a news release more arrests and charges are expected.

The charges against Watetch, Burns and McKay were laid after an 18-month investigation. The three were set to appear in Prince Albert Provincial Court on Monday morning.