Four homeless men were found beaten to death in Manhattan early Saturday morning in what police are calling a random attack. A fifth man is in critical condition.

All five victims were men who suffered trauma to the head, police said. They appeared to have been sleeping when the attack happened just before 2 a.m. in the Chinatown area.

Two witnesses on the scene told officers that a man in a black jacket and black pants struck a victim in the head with a metal object multiple times, then left, said Assistant Chief Stephen J. Hughes, Commanding Officer Patrol Borough Manhattan South at a press conference Saturday. 

A 24-year-old man, who appeared to be homeless, has been taken into custody, police said. Police could not say if the suspect was found holding the pipe.

“We did recover a weapon — a pipe — close by. I’ll leave it at that," said Deputy Chief of Manhattan South Detectives Michael Baldassano.

Baldassano said the crime appeared to be a random attack.

Police responded at 1:49 a.m. to a 911 call of an assault in progress in the Chinatown area. When they arrived, officers found an adult male, unconscious and unresponsive, with severe trauma to the head. EMS pronounced the man dead.

A second man, 49, was taken to New York Downtown Hospital in critical condition.

Police later discovered three more men in the area, all who had died.

An investigation is ongoing and police are conducting a street-by-street canvas for additional victims, Hughes said.

Giselle Routhier, policy director at the advocacy group Coalition for the Homeless, called the attack "unfathomable in its brutality."

"It should serve as a reminder to all of us that our homeless neighbors live without the protection and privacy of a home. They are our fellow human beings and deserve the dignity and safety that a home assures. New York City and New York state must build enough deeply subsidized housing for homeless New Yorkers to match the scale of the need in order to prevent such a tragedy from ever happening again," she said.

Researchers say homelessness in the city has increased in recent years, driven primarily by the lack of affordable housing.

Thousands of homeless people sleep on the streets of New York City every night, and the large majority are people living with mental illness or other severe health problems, researchers say. 

African-American and Latino New Yorkers are also disproportionately affected by homelessness, the Coalition says.

"We’re stunned and horrified by this senseless act of violence against the most vulnerable members of our community," Mayor Bill de Blasio said in a tweet Saturday.

Police asked anyone with information or who have experienced a similar crime to get in contact the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782). Tips can also be submitted online or on Twitter at @NYPDTips.

This article originally appeared on USA TODAY: Homeless men beaten to death in Manhattan random attack, police say