Protests over grand jury decisions not to indict the police officers responsible for the deaths of Eric Garner and Michael Brown continued in Oakland last night. Tensions came to a head last night when an undercover cop who had been marching with protesters pulled out a gun on demonstrators.

According to NBC News, upwards of 100 protesters traveled through Oakland and Berkeley, Calif. last night. There are few details at the time, put NBC News reports that the officer pointed his gun at the crowd after being attacked.

On Monday night, protesters in Berkeley shut down both lanes of traffic on Interstate 80, blocking traffic for two hours.

[via NBC News]