Tompkins Square Park, Anticipating Protesters, Is Chained Shut Just after 10 p.m. on Tuesday, James Drysdale was about to enter Tompkins Square Park when he was surprised to find his passage barred by a metal gate chained shut at East Seventh Street and Avenue B. The other gates around the 10-acre park in the East Village were also chained shut, long before the park's normal midnight curfew. Mr. Drysdale, 33, an architect, said he wondered if there had been a violent crime in the park. Others in the area, however, said the police had closed the park one to two hours earlier, apparently in response to an Occupy Wall Street march consisting of several dozen people who paraded down Avenue A in support of students in Montreal who had marked on Tuesday their 100th day protesting tuition increases. A participant in the New York march, Keegan Stephan, said that it had followed an event held earlier in the evening inside Washington Square by an Occupy-related group called the Free University. Around 8 p.m., he said, the marchers started heading east on 10th Street, announcing Tompkins Square as their destination. Mr. Keegan raced ahead on his bicycle and found police officers also arriving at Tompkins Square, well before the marchers. "Before the march was visible or audible from the park, police came up in cars and closed the park," he said. It was the second time in recent weeks that the police shut the gates early at Tompkins Square, a city park with a long history of confrontations between the police and protesters over, among other things, curfew enforcement. On April 14, the police ordered people to leave Tompkins Square and chained the gates shut after participants in a Greenwich Village march struck the window of a Starbucks with a metal pole and scuffled with officers, the authorities said, before passing by or through Tompkins Square. The police did not immediately respond to an inquiry about the reasons for closing the park. Mr. Stephan said that on Tuesday, the marchers passed along Avenue A for about two blocks, passing part of the park, then headed back west on St. Mark's Place. As the procession passed along Avenue A, he said, officers prevented people from entering or leaving through some park entrances. Afterward, he said, the police announced to dozens of people inside the park that they had to leave. By 10 p.m. the supporters of the Canadian students had long since departed, but people who showed up to Tompkins Square expecting an evening stroll beneath the trees instead found the locked gates. Some wondered why the park was closed in the absence of any visible disturbance or emergency. "It just feels creepy that this public gem is being closed down," Mr. Drysdale said. John Greene, 61, said officers told him around 9 p.m. that they had closed the gates to prevent protesters from damaging the park, an explanation that he found not particularly persuasive. "I see no reason for it," Mr. Greene said of the closing, adding that the marchers "should be allowed to express their opinions in the venues most attractive to them."