Seven people were caught on camera climbing out of a Brooklyn sewer manhole early Friday before fleeing in waiting vehicles, prompting an NYPD investigation into the bizarre incident.

The group emerged from a manhole around 2 a.m. on McDonald Avenue in the Gravesend neighborhood, according to surveillance footage obtained by The Flatbush Scoop. The video shows a person removing the manhole cover before several more climbed out of the sewer system one by one.

Some of them appeared to be holding flashlights and wearing waders, gloves and heavy-duty boots commonly used in wet or hazardous environments. After reaching the surface, the group gathered near two parked cars, where they appeared to remove dirty gear and load equipment into the vehicles before driving away.

The incident came just an hour after a similar scene unfolded elsewhere in Brooklyn. Eight people were recorded around 1 a.m. entering a sewer manhole near Heyward Street and Bedford Avenue in Williamsburg, according to News 12 Brooklyn. The group later emerged and left the area in a waiting vehicle.

Investigators are working to determine whether the two incidents are connected. Police examined the Gravesend location Friday afternoon and later said the area was “safe and free of hazards,” according to a social media post. However, the reason for the group being underground remains unknown.

The NYC Department of Environmental Protection also told News 12 Brooklyn in a statement that it did not find any damage to the sewer system at the Gravesend site.

“Entering the sewer system is both illegal and extremely dangerous. Sewers can contain numerous hazards, including noxious and potentially deadly gases, unstable surfaces, flooding risks and confined spaces. For these reasons, members of the public should never enter a pipe, drain, catch basin, manhole or outfall,” a DEP spokesperson told the outlet.

No arrests have been made, and the investigation remains ongoing.

The Independent has contacted the NYPD and the DEP for comment.