New York City police officials said Tuesday they will deploy drones to assist in rescue missions, traffic-accident investigations and large-scale events, a move that raised privacy concerns among civil-liberty advocates.

Members of the New York Police Department’s Technical Assistance Response Unit, or TARU, will use 14 drones, which will cost the department $480,000 in 2019, according to an NYPD spokeswoman. A member of the unit will operate a drone remotely to make three-dimensional projections of traffic accidents, search for evidence and collect details in spills involving hazardous material. Chief of Department Terence Monahan said it is the first time the NYPD will be deploying the drones in public.

The devices, which have thermal sensors to detect a person’s heat energy, will also be used to monitor large events and hostage situations, according to a copy of the NYPD’s policy on the technology obtained by The Wall Street Journal.

RYAN OF TOYSREVIEW, 7, IS YOUTUBE'S HIGHEST PAID STAR

The NYPD is restricted from using the drones to perform routine patrol, surveillance without a warrant or traffic enforcement. However, the policy leaves the door open for the NYPD to use the technology in other incidents related to “public safety, emergency, or other situations with the approval of the Chief of Department.” The devices aren’t equipped with any weapons, a spokeswoman said.

The NYPD met with and provided a draft of its drone policy to the New York Civil Liberties Union before completing its program. NYCLU associate legal director Chris Dunn said he expressed concerns regarding police use of the technology.

“Police cameras in the skies of New York City offer a new frontier for both public safety and abuses of power,” Mr. Dunn said.

In a statement, the Legal Aid Society said it opposed police use of the technology. “Its continued unrestrained expansion will only further sow distrust and increase unequal treatment of our clients,” the organization said in a statement. “This is a dangerous step towards the further militarization of the NYPD.”

To read the rest of this story, which was first published in The Wall Street Journal, click here.