Police Commissioner Ray Kelly says at least 20 offensive comments posted on Facebook about the West Indian Day Parade were made by city police officers.
The comments, apparently made in response to violence at the parade, were posted under the officers' full names and pictures.
The page has since been taken down.
Some of the postings included, "They should bring in the National Guard!!! Let the government handle these animals," and "Maybe next year they should hold it on Rikers Island."
Mayor Michael Bloomberg, who addressed the controversy for the first time on Wednesday, says it's
"If it's true, it is totally inappropriate. I think you can pick lots of adjectives that are saying that this is something nobody should be proud of," Bloomberg said.
Meanwhile, the New York Civil Liberties Union has come out in defense of the officers' freedom of speech.
"Police officers like other government employees have a right to free speech in their private lives, and they even have the right to say obnoxious and offensive and racist things," said New York Civil Liberties Union Executive Director Donna Lieberman.
Commissioner Kelly released a statement saying "The Police Department reserves the right to discipline behavior it determines to be unbecoming of a police officer or detrimental to the service, especially when it is disrespectful of communities that officers have taken an oath to protect."