Columns of officers were seen swarming from several direction around City Hall and began to remove tents.
The massive deployment comes as police are facing down hundreds of chanting protesters at several intersections near City Hall. The protests have been peaceful and demonstrators were respecting the police
Police have been converging on the stadium all evening as they prepare to take down the camp. In recent minutes, Metro buses filled with officers have left, headed downtown.
Some LAPD officers are already facing down protesters on the streets around City Hall. Deputy Chief Jose Perez, the incident commander for the night's operation, said he had asked lawyers from the National Lawyers Guild -- a group that has served as an informal intermediary between police and protesters -- to fan out among the protesters and tell them they will have "a reasonable amount of time" to leave the park after the dispersal order is given.
"Those who want to be arrested will be. Those who don't, won't," Perez said in a brief interview. The LAPD has closed off an area from Temple Street on the north to 3rd Street on the south and from Alameda Street on the east to Broadway on the west.An LAPD helicopter announced the start of the department's action, swooping low and incessantly circling the City Hall steps on which hundreds of protesters had gathered. It flooded the camp with light from its high-powered searchlight and the din from its propellers threatened to drown out a chant of "Occupy L.A., all day, all night!" by the protesters.
Someone then launched fireworks over the camp.