A Brazilian man is in hospital recovering from gunshot wounds sustained after he approached two men taking drugs on the Porto Metro. His assailants, believed to be local men, are still at large.
As far as police can tell, an argument broke out after the victim, travelling in the same carriage on the blue line to Matosinhos, tackled the men over their behaviour in full view of everyone on board. One brought out a 6.35 millimetre pistol and shot the man as he turned away.
The assailants then got out at the next station (Vasco da Gama) and ran, leaving their victim to stagger out of the train after them.
CCTV images show the Brazilian then being helped by another passenger who persuaded him to return to the train and travel to the stop nearest to Hospital Pedro Hispano.
The two walked into Casualty, where the Brazilian was then taken for surgery.
Police called to the scene, later searched the Metro train for evidence.
According to news reports, this was the first time in the 12-year history of the Metro that an incident of this kind had been reported.