Police are searching for four teenagers who beat and tried to rob a delivery man in Manhattan.

Police say surveillance video shows three of the teens beating a man in a hallway at 420 Morningside Avenue in Morningside Heights on Friday afternoon, while the fourth acted as lookout.

Police say they ordered Chinese food, then waited outside the sixth-floor elevator for the deliveryman to arrive.

They beat him and tried to get money from his pocket, but he had no cash on him.

They ran off toward Morningside Park.

Some residents who live in the building say they've noticed strangers coming and going and will now be on alert.

"Sometimes there's a stranger or someone I don't know going inside. I worry they'll go inside and take something. It is usual here. So I wish there were more serious security," said one tenant.

"I think anyone who attacks another human being, that just breaks my heart to hear something like that," said another.

The victim, who was punched in the eye and left with a bloody mouth, is said to be doing okay.

Police say all four suspects are between 15 and 19 years old.

All were seen wearing jeans and dark puffy jackets or hoodies.

Anyone with information on the case should contact the Crime Stoppers hotline at 1-800-577-TIPS, or text CRIMES and then enter TIP577, or visit www.nypdcrimestoppers.com.