While the exact circumstances of their deaths are still unknown, Portuguese media reported that the couple were apparently unable to move quickly enough to avoid being trapped by the rapid rise in the water level.

"Two people lost their lives after their home was flooded" in Seixal, in the Setubal region, a spokesman for the National Civil Protection Authority told AFP, without providing further details.

Setubal was one of the areas hardest hit by Storm Claudia, which has swept both mainland Portugal and the island of Madeira with heavy rain and strong winds since Wednesday.

The civil protection agency recorded nearly 1,000 incidents, mostly floods and fallen trees, which in some cases have blocked roads or damaged vehicles.

Up to 20,000 homes and other electricity consumers were left without power at dawn on Thursday, according to the electricity distributor E-REDES.