A 23 year-old was shot in the head on Tuesday at Olhão train station.
Police are investigating the background to the incident which happened at around 18:00hrs in an area where members of the public were standing.
The still conscious victim was rushed to Faro Hospital by the ambulance service and underwent surgery.
The round had not pierced his skull and ammunition cases were found nearby.
Several shots had been fired but only one had hit the target. Two young men approached a group of five others and one of them opened fire.
This police say only there was an attack "by a group of people on another group."
There is a current quarrel between two rival gangs which kicked off two weeks ago. This shooting is likely to be related and the police already have identified a suspect.
