3 people spotted climbing out of sewer on Manhattan's East Side, police say

There's been yet another sewer intrusion, authorities said Wednesday. 

This time it took place on the East Side, at Park Avenue and East 61st Street. 

The NYPD said it received a 911 call at 4:35 a.m. saying three people were spotted climbing out of a sewer. The trio then drove away in two separate vehicles, which headed off northbound on Park Avenue, police said. 

Emergency responders remained on the scene to make sure everything below ground was secure. The area was deemed safe, and nothing suspicious was found below ground.

So far there's no word of any arrests.   

The incident took place amid heightened security measures in the area for the United Nations General Assembly. It's just the latest in a series of recent incidents across New York City. There's even been a recent similar incident on Long Island. 

Police sources have previously said these sewer intruders may be either treasure hunters or urban explorers. Several men faced criminal mischief and burglary charges in a similar incident in Brooklyn last year. 

The city's Department of Environmental Protection has repeatedly warned people not to enter the sewer system, saying sewers "contain numerous hazards, including noxious and potentially deadly gases, unstable surfaces, flooding risks, and confined spaces."