Police say they are investigating the death of a man inside New York City's main intake shelter for homeless men as a homicide.

Manhattan Chief of Detectives William Aubry said the 56-year-old victim was found in a bloody room, lying on his back with neck injuries.

He says all 67 people who checked into the shelter's third floor Thursday are being interviewed.

There were three beds in the victim's room.

Human Resources Administration Commissioner Steven Banks says 30 shelter guards worked Thursday night.

Officials have struggled to serve the city's growing homeless population in recent years. Shelter safety has come under particular scrutiny following some high-profile crimes involving the homeless.

Banks says the city has trained more guards.