Police have arrested dozens of people during a raid of an Occupy San Francisco encampment outside the Federal Reserve building early Sunday.

San Francisco police Officer Albie Esparza says that around 4 a.m. officers arrested about 55 people for illegal lodging.

No officers or demonstrators were injured, but Esparza says some officers were spit on and one officer was pushed by demonstrators during the arrests.

Esparza says that before police moved in on the encampment demonstrators had been warned on an hourly basis over a 24-hour period that they were subject to arrest.

The arrests Sunday come after at least 85 people were arrested Wednesday when police cleared a separate Occupy encampment in nearby Justin Herman Plaza.