The incident happened on 23 August in an area used by customers, in front of several shops. No injuries were reported.

Oeiras Parque said the incident followed a period of "intense and unexpected rain" at a time when maintenance work was being carried out on the roof of the building.

Water entered through the roof and caused damage to the ceiling in a limited area of the shopping centre.

A team from the Paço de Arcos Volunteer Firefighters was called to the scene during the afternoon, with the incident confirmed to Lusa at around 4.15pm.

As a precaution, access to the affected section was immediately restricted, and several shops located in the area were temporarily closed.

The rest of Oeiras Parque remained open and continued operating normally.

Technical teams from the shopping centre were also called to assess the affected area, working alongside the company responsible for the maintenance work taking place at the building.

Oeiras Parque said the shops that were temporarily closed would reopen once the assessment was completed and the necessary safety conditions were confirmed.

RTP reported that the collapse was linked to rainwater infiltrating through the ceiling. Oeiras councillor Sílvia Breu told Antena 1 that the situation had been quickly resolved without injuries and that cleaning operations had been completed.

The incident came as unusually unsettled weather affected much of mainland Portugal over the weekend.

The Portuguese Institute for Sea and Atmosphere (IPMA) had forecast periods of heavy rain and thunderstorms, while strong wind gusts were also expected in some areas.

The weather was associated with a depression northeast of the Azores and an accompanying frontal system moving towards mainland Portugal, bringing conditions described by meteorologists as unusual for this time of year.

Unstable conditions are expected to continue into the week, particularly across northern and central Portugal.