Superintendent of Porto's Public Security Police, Pereira Lucas, said there were measures in place to mitigate threats but that on a global level, in terms of intelligence services, "no additional elements" deserved concern.

He said that this year, as well as barriers preventing the circulation of vehicles, there would also be two or three additional safety measures as a consequence of the evolution of terrorists' ways of acting.

Lucas added that police forces would be attentive to risk profiles and would act accordingly if these were identified, which might involve contention measures and removing them from the area.

The Aliados Avenue will be the main site for New Year's Eve parties, with fireworks and a concert taking place after midnight.