NEW YORK CITY (WABC) -- NYPD investigators have released pictures of two men they say vandalized a subway station during a citywide protest last week.
Police arrested more than a dozen protesters at Grand Central Terminal who participated in the demonstration Friday.
Investigators say the two men in the new surveillance pictures were part of a criminal effort to vandalize the MTA subway system during that protest.
Vandals poured glue in MetroCard readers and propped open an emergency gate at the 96th Street B/C station so people could ride for free, and they spray painted OMNY payment systems leaving it to MTA workers to clean up.
They also set a trash can on fire and broke windows outside the station at 96th Street.
Police say the suspects seen in the photos were part of a larger group of protesters who were demanding free subway rides and fewer police in subway stations.
Those demonstrators led a large march through Grand Central at rush hour, trying to disrupt the commute.
Not all the demonstrations were destructive, but at least a few people turned to vandalism.
"I think that was amateur hour," Police Commissioner Dermot Shea said. "I think that gives good, hard-working protesters a bad name. That was ridiculous."
Police say they are still working to identify and arrest other vandals.
"This was not a protest," Shea said. "This was criminal activity by misguided people, by a bunch of knuckleheads quite frankly. I mean, lighting garbage can fires in the transit system. What could possibly go wrong with that?"
Anyone with information is urged to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
You can also submit tips by visiting the CrimeStoppers website at crimestoppers.nypdonline.org or by messaging on Twitter @NYPDTips.