The manhole mystery gripping New York City continues as police announced that three more men were spotted climbing out of the sewer system in Brooklyn early Friday morning.

NYPD officials said a witness called 911 to report the incident around 4:30 a.m., and directed officers to the intersection of Bay Ridge Parkway and 17th Avenue in Bensonhurst.

The caller reported seeing three men emerge from the manhole in brightly colored clothing, but by the time police arrived at the scene, the manhole was closed, officials said.

Investigators were canvassing for surveillance video, and police did not make any immediate arrests.

The incident comes just after police arrested two men for climbing out of a manhole on the Upper East Side on Wednesday – an event that led police to step up security in the area, given its proximity to dignitaries visiting for the U.N. General Assembly.

Officials said police took 26-year-old Kevin Rodriguez of Flushing, Queens into custody around 5:30 p.m. Thursday, alongside 25-year-old Samuel Reveron of Elmhurst, Queens. Both were arrested in the NYPD’s 13th precinct, which includes neighborhoods in south Midtown.

They were charged with trespass and conspiracy, according to the NYPD. Information for their lawyers was not immediately available early Friday.

The Bensonhurst sighting is the latest in a string of reports of people climbing out of manholes over the last few months, from Penn Station to Gravesend and Williamsburg. The incidents have caused major speculation about the motives of the subterranean climbers, many of whom have been captured on surveillance footage as they emerge and disappear into the night.

In response to the Upper East Side incident, NYPD spokesperson Brad Weekes said people have been known to enter the sewer system “to look for valuables and other scrap metal after a storm.”

This is a developing story and may be updated.