The Los Angeles County Sheriff's Department will seek charges against at least 21 California inmates involved in racially motivated rioting that has left two prisoners dead and more than 100 injured, officials said Thursday.

Seven are suspects in the death of Wayne Tiznor, 45, a black inmate who was killed during the first wave of violence, Sheriff Lee Baca said. The others include 10 inmates at the Pitchess Detention Center in Castaic, and four at the Men's Central Jail in downtown Los Angeles.

Those numbers are expected to grow as sheriff's detectives put together cases and search for ringleaders, Sheriff's Cmdr. Dennis Burns said. Meanwhile, jail administrators tried to hold down racial tensions in the lockups by offering prisoners privileges in exchange for good behavior, and by encouraging them not to respond to exhortations from gang leaders to fight.

Prisoners have been on lockdown — with few privileges other than standard medical care — on and off since the melees began Feb. 4. But Baca said that starting Thursday, inmates began receiving mail, and dorms where inmate life remained peaceful would soon have most if not all perks restored, including visits and phone calls.

In a separate attempt to quiet things down, the department has moved most of Pitchess' highest-risk offenders out of the large dorms where they lived, to single and double cells at the Men's Central Jail and other places, the sheriff said. Because the violence was racially based, the department also had separated inmates in some facilities by race. But by Thursday, most were again living in mixed dorms, Baca said.