A citywide tactical alert was issued by the Los Angeles Police Department after a group of protesters began taking over streets of downtown Tuesday night, injuring one officer.

The group began to gather at around 9 p.m.

Police began receiving reports of the protesters surrounding Department of Homeland Security patrol cars and allegedly trying to take over a Metro bus, ABC7 reports.

According to LAPD Chief Michel Moore, officers attempted to disperse the group, but the crowd began throwing rocks and bottles.

The condition of the injured officer was not released.