The man and woman attacked him in the lobby of an Olinville Avenue apartment building, police said. View Full Caption NYPD

THE BRONX — A Bronx deliveryman was stripped half-naked by a man and woman who beat and robbed him in the lobby of an apartment building with a crowd of people standing by, according to an NYPD video.

One of the onlookers even casually bounced a basketball during the attack, the video shows.

The 21-year-old deliveryman was confronted in the lobby of 2802 Olinville Ave., near Britton Street in Allerton, about 11 p.m. on Feb. 2, police said.

It's unclear why police took nearly three weeks to publicize the attack.

A group of people in the lobby looked on as the pair started punching and kicking him, the video shows. None of them offers any assistance.

At one point, the woman, wearing a gray hoodie with Puma sneakers, is seen grabbing the victim's jacket and pulling it off over his head.

The suspects continue to punch and kick the victim repeatedly before the woman stops to rummage through the victim's jacket. They grabbed his iPhone 5S and some cash before fleeing, police said, leaving the deliveryman sitting shirtless in the lobby.

The robbers hadn't been arrested as of Tuesday morning, according to authorities.

Photos of the suspects taken from nearby locations were also released by the NYPD Tuesday.

Anyone with information should contact Crime Stoppers at (800) 577-TIPS (8477).