A man has been taken into custody after allegedly killing two people and injuring a third in an apparent unprovoked stabbing spree in Manhattan, authorities said.

The first victim, a 36-year-old man, was fatally stabbed in the abdomen at 8:22 a.m. Monday in an unprovoked attack by the construction site where he was working on West 19th Street, the NYPD said.

About two hours later, a 68-year-old man was fatally stabbed multiple times on East 30th Street, police said.

The third victim, a 36-year-old woman, is in critical condition after being stabbed multiple times around 10:55 a.m. at 42nd Street and First Avenue, police said.

The 51-year-old suspect -- who lives at the Bellevue Men's Shelter on East 30th Street -- appeared to pick the victims at random, police said.

He was apprehended around East 46th Street and 1st Avenue, police said.

"He just walked up to them and began to attack them with the knives," Chief of Detective Joe Kenny said at a news conference.

The suspect has eight prior arrests, according to law enforcement, and is believed to have severe mental health challenges, Mayor Eric Adams said.

"There’s a real question as to why he was on the street," Adams said.

Two bloody kitchen knives have been recovered, police said.

"These random attacks left two innocent victims dead and another fighting for her life," Kenny said. "We do have a suspect in custody and we are not looking for any others at this time."