NEW YORK (CBSNewYork) — The search continued Wednesday for the hammer-wielding man who police say randomly attacked at least four people in Manhattan.

The first attack happened at around 1:45 p.m. Monday near West 35th Street and Sixth Avenue. There were also attacks that evening at Madison Square Park, Union Square Park and West 17th Street between Fifth and Sixth avenues.

As CBS2’s Ilana Gold reported, police are on the lookout for the suspect. They say they know who he is and are working to track him down.

Police have posted signs with the suspect’s photo and are offering a $2,500 reward for any information leading to his arrest.

During an exclusive interview with CBS2, one of the victims, Victor Urena, showed his head injury after he got attacked with a hammer on West 35th Street.

“I started bleeding right away,” he said. “I checked myself. Had blood on my hand.”

Union Square Hammer Attack Suspect

Police have released a photo of a man wanted in connection with two hammer attacks near Union Square. (credit: NYPD)

The 20-year-old had just left class at Mercy College when, police say, the man attacked him.

“You don’t expect that from no one,” Urena said.

A 33-year-old victim who was assaulted on West 17th Street spoke to CBS2. She said she had just left dinner with her boyfriend at 7:30 p.m. when she was attacked.

“I was walking to the train station in Union Square and someone came up behind me and yelled something and then the next thing I know I was struck in the head,” said the woman, who did not want to be identified. “I initially I thought I got punched, but later on when I looked at my hand, I was bleeding.”

Police say the suspect has a criminal record and mental health issues, 1010 WINS’ John Montone reported.