Two police officers in the western U.S. city of Los Angeles have been disciplined for an incident in which several protesters and members of the news media were injured at a immigration rights rally last week.

Los Angeles Police Chief William Bratton announced Monday that deputy chief Cayler Carter will be demoted one rank and required to stay home from work while investigations into the incident continue. Another top officer, Louis Gray, has been reassigned within the department.

There are at least four investigations into last Tuesday's events. Reports said some 30 activists threw rocks and bottles at police, who retaliated with batons, rubber bullets, and shoving. Some observers say the police fired indiscriminately into a crowd of hundreds of peaceful marchers rather than target the troublemakers. At least three demonstrators have filed lawsuits against the city.

The Los Angeles police department has been criticized in the past for violent incidents. Most notable was the 1992 beating of a black taxi driver, Rodney King, 16 years ago. The acquittal of the white policemen involved sparked days of deadly riots in South Central Los Angeles.

Some information for this report was provided by  AP and Reuters.