The incident happened on Saturday as thousands of anti-Wall Street protesters held a demonstration in the famous square in Manhattan.
“These protests are already making a difference. The dialogue is now happening all over the world,” Reuters quoted New York protester Jordan Smith as saying on Saturday.
Earlier in the day, police arrested 24 people at a Citibank branch near Manhattan's Washington Square Park on charges of trespassing after they ignored a request by the bank to leave, police sources said.
The protesters are angry that the major stockholders of the banks are enjoying booming profits after getting bailouts in 2008, while most US citizens are struggling in a difficult economy with more than 9 percent unemployment and little help from Washington.
Inspired by the Occupy Wall Street movement, demonstrations were held in Asia on Saturday and rippled through Europe back to the United States and Canada.
In the United States, protesters took to the streets of cities from Washington, Boston and Chicago to Los Angeles, Miami, and Toronto.