A high school student was robbed and stabbed in Manhattan after using the new Facebook Marketplace feature to try and sell sweatshirts, police say.

The 17-year-old Stuyvesant High School student took three hooded sweatshirts down to Pier 26 after school on Friday to complete a sale he started on Facebook, his friend Nazum Uddin told NBC 4 New York.

When the student arrived at the Tribeca skate park where he had agreed to meet the female buyer, there were some surprise visitors.

Three other people approached him, one wearing a ski mask.

"He brought the clothing to the skate park after school, and when he got here they pressed upon him and stabbed him and grabbed his clothing and ran away," Uddin said.

Police confirmed the student was stabbed in the left thigh and was robbed of the sweatshirts.

Facebook recently introduced a new 'Marketplace' feature on its platform, where people can sell things to one another peer-to-peer.

NBC 4 New York has reached out to Facebook for comment.