An 18-year-old boy was stabbed in the back and another man injured when they were attacked in Hell's Kitchen Tuesday, police said.

The teen, who was not identified, was assaulted in front of Crispin's restaurant on 52nd Street and 10th Avenue, police said. He was taken to Weill Cornell Medical Center.

The second man, who was also not identified, was slashed in the back and taken to Mount Sinai Roosevelt hospital, police said.

Luis Arce, a waiter at Crispin's, said he saw a group attack the 18-year-old. "He couldn't get up," Arce said of the victim.

The reasons behind the attack were not immediately clear.