"Earlier in the afternoon, as many as 10 Department of Correction buses, big enough to hold 20 prisoners apiece, had been dispatched from Rikers Island in what one law enforcement official said was “a planned move on the protesters.”

Etan Ben-Ami, 56, a psychotherapist from Brooklyn who was up on the walkway, said that the police seemed to make a conscious decision to allow the protesters to claim the road. “They weren’t pushed back,” he said. “It seemed that they moved at the same time.

Mr. Ben-Ami said he left the walkway and joined the crowd on the road. “It seemed completely permitted,” he said. “There wasn’t a single policeman saying ‘don’t do this’.”

He added: “We thought they were escorting us because they wanted us to be safe.” He left the bridge when he saw officers unrolling the nets as they prepared to make arrests. Many other who had been on the roadway were allowed to walk back down to Manhattan."