The flights were diverted to Porto, Faro and Madrid a source from airport management company ANA – Aeroportos de Portugal told Lusa News Agency.

The source said that of the 18 flights, 11 were diverted to Sá Carneiro airport, in Porto, three were diverted to Faro airport and one to Madrid, Spain.

According to Ana the fog at Lisbon airport also meant that two flights from Lisbon from Porto and one from Faro do Lisbon were grounded.