A crowd gathered on Saturday in Cadman Plaza, in downtown Brooklyn, to protest the Department of Parks and Recreation’s closing of the thesis exhibit of the Brooklyn College Masters of Fine Arts program. Held at the Brooklyn War Memorial, the exhibit was shut down on Thursday, the day after it opened, following claims that two or three of the works showcased sexual content that could be offensive to visitors.

Though no particular artwork was cited, some of the more sexually explicit pieces included watercolor paintings of gay male sexuality and a foam rendering of male sex organs encased in a lightbox.

“Upon viewing the exhibit, the Borough Commissioner [Julius Spiegel] made the decision that the work, in fact, was not appropriate for families, and closed the show,” said Warner Johnston, a spokesman for the parks department. The war memorial is a public space within Cadman Plaza and is thus under the authority of the parks department, which changed the locks on the building to prevent students from accessing their work.

“Unlock the art,” protesters screamed at the rally, forming a barricade in front of the concrete memorial and holding signs reading “have a heART” and “Plan C(ensored),” a play on the exhibit’s original title, “Plan B.”

Demonstrators on Saturday also protested the announcement that the school would not pursue reopening the exhibit at the war memorial. “In keeping with the public nature of the space, as well as its position as an honored war memorial, Brooklyn College has respectfully decided to move the entire student exhibit to our campus,” said Roberta Matthews, provost of Brooklyn College, in a statement released on Friday evening. “The administration of the college has supported our students’ rights to freedom of artistic expression.”

Others affiliated with the school supported the decisions of both the parks department and the college administration. “I don’t object to the parks department decision whatsoever since the facility is regarded as family appropriate,” said Jeffrey Wiesenfeld, a member of the City University of New York’s board of trustees and a partner at Bernstein Investment Research and Management. “I have no problem with it being on campus. The only thing I would say is that it’s really not the best use of public dollars,” he said, adding that he did not believe the closing of the exhibit at the war memorial site was a First Amendment violation.

But a prominent civil liberties attorney and a former director of the New York Civil Liberties Union, Norman Siegel, who attended the rally, called the actions of the parks department, “censorship, pure and simple.”

Mr. Siegel also referred to the 1999 battle between the Giuliani administration and the Brooklyn Museum of Art over its “Sensation” show, which featured controversial work including a depiction of the Virgin Mary decorated with elephant dung. After the Giuliani administration threatened to cut funding to the museum, the museum sued the city and prevailed.

Mr. Siegel said he intends to ask the museum to support the Brooklyn College students in their fight, and added that he was surprised that a similar situation could happen under the Bloomberg administration.

“One would hope that Bloomberg, who has been a huge supporter of the arts, would get on the phone and tell the parks department that what they did was wrong and that they should reopen it,” Mr. Siegel said. “New York has a rich history of support for artistic expression and this should not be going on anywhere, let alone New York City.”

“We’re ready to fight,” said an MFA student, Megan Piontkowski, 25. “We really think that this is wrong, and we’re willing to do what it takes.”

“We create art to be seen and to communicate,” said an MFA student, Zoe Cohen, 28. “Now we’ve lost that ability.”

In addition to questions of civil liberties, some students argue that the college does not have a suitable space to display the exhibition on campus and that moving the art could potentially destroy many of the works produced for the show.

Marni Kotak, 31, who built a site-specific mock classroom installation, called the administration’s suggestion “unacceptable.” “Many of the works they couldn’t move without either us dismantling them or them destroying the property,” she said. “We’re just so frustrated. And we’re so disappointed because the school said they were supporting us.”

The art department faculty is equally disturbed. The chairman of the Brooklyn College graduate art program, Michael Mallory, who attended the rally, said he thought the college should have taken more time to consider its options, and that he did not believe the school had an adequate venue to host the exhibition.

Mr. Mallory also said he was surprised by the hasty reaction of the parks department, since previous Brooklyn College MFA thesis shows held at the war memorial didn’t exactly showcase “homogenized content.”

“If you are putting up a contemporary art show,” he said, “chances are there are going to be controversial things in it. If you don’t expect that and anticipate it, I suggest you better look around. We don’t do academic history paintings anymore.”

To be sure, though, public reaction to the closing hasn’t been entirely critical. “You cannot have artwork of a penis in a display where families might visit it,” wrote an anonymous commentator on the MFA student’s blog, plancensored.blogspot.com. “If closing the exhibit is what it takes to send you the message, so be it.”

For MFA students, the exhibit promised a chance to showcase the results of two years of work and many thousands of dollars of tuition and expenses. “MFA shows can potentially jumpstart an artist’s career,” explained Ms. Piontkowski. Now, some students have modified their expectations. “You put all this work into your piece,” Ms. Kotak said with a sigh, “You kind of hope that the show will actually happen.”