The NYPD has reportedly spotted posts on social media calling for cop killings on New Year's Eve, following a period marked by an uptick in threats made against police officers.

DNAinfo reports that gang members have taken to Twitter to make threats against cops, using hashtags like #wingsonpigs and #onlydeadcops. Some of these tweets call tonight "Kill A Pig Night" and "New Year's Eve Massacre 2014."

The NYPD has been investigating a large number of threats made against the department recently, following the fatal December 20th shooting of Officers Rafael Ramos and Wenjian Liu. DNAinfo reports that cops have arrested at least 16 people in connection with these threats, including Queens resident Elvin Payamps, who was allegedly overheard threatening to "kill another cop" on his cellphone last week.

The city will be on particularly high alert tonight, with thousands of people packing into Times Square for the NYE celebrations. Protesters have also reportedly organized planed demonstrations in Midtown. "In the event there are any protests tomorrow night, we have a detail set up for that, as we’ve had over the last five or six weeks. As with any new year’s eve detail, we’re absolutely concerned about the safety of everyone there - including the police officers," NYPD Chief of the Department Jim O’Neill said at a press briefing yesterday. "There is obviously a heightened sense of security during this detail. So as we turn the police officers out, we remind them that they have to look out for each other."

The NYPD says they've been looking into a total of 63 recent threats made against the cops and the mayor.