Saturday marks the first full day of Marines on duty in Los Angeles, one week after protests against Immigration and Customs Enforcement raids ignited in LA.

The troops are authorized to detain people who pose a threat to federal personnel or property, but only until police can arrest them.

In a news conference on Friday, the city’s police chief, Jim McDonnell, said his agency was “fully prepared” and that officers would be focused on balancing a need to “protect public safety while safeguarding every individual’s right to protest peacefully.