The protesters had said the planned cleanup at 7 a.m. was merely a pretext to evict them.
They've been camped out there for a month in a protest over wealth distribution that has inspired similar demonstrations across the globe.
Supporters streamed into the plaza early Friday before the announcement.
There was a strong police presence, and a showdown between protesters and authorities had been feared.
(Copyright 2011 by The Associated Press. All Rights Reserved.)