A 15-year-old boy was stabbed while riding a Bronx train when a five-person crew tried to rob him and his friend late Tuesday, police said. 

The teen boarded a No. 6 train at Hunts Point Avenue with an 18-year-old pal just after 10 p.m., when five strangers confronted them and demanded their belongings, which they refused, authorities said. 

The crew then snatched the older victim’s bag, although he managed to grab it back, according to police. 

But one of the brutes then knifed the 15-year-old on the left side of the torso, cops said. 

The menaces bolted from the train at the next stop, Whitlock Avenue, according to police. No arrests had been made by Wednesday afternoon. 

The younger victim, who was bleeding, was taken to Jacobi Medical Center, where he was listed in stable condition, police said. 

The older teen did not sustain any injuries during the confrontation, police said.