This, after the protesters seem to have won.

UPDATE: Observers on the scene have tweeted that the police are positioning paddy wagons around the park.

According to the tweets we're seeing, there are cops guarding the bull at Bowling Green, which is where we saw the crowd heading as they marched after they heard that the park would not be cleaned.

As for this arrest, we're not exactly sure how this happened, but our Julia La Roche grabbed this picture as she was leaving the park. We'll keep you updated as we know more.

And according to CNBC's John Carney, the police are getting into position on the streets.

More arrests via Julia La Roche: