A passenger vehicle veered off the road on Saturday morning on Highway 4 (A4), near Santa Comba de Rossas, in Bragança.
The alert was given at 7:03 AM, and the injured were transported to Bragança Hospital, as confirmed by Civil Protection.
Traffic is, however, flowing normally.
In addition to firefighters, the National Institute of Medical Emergency (INEM), the National Republican Guard, and representatives of the highway concessionaire are at the scene.
In total, 16 operatives, supported by six vehicles, responded to the incident.