"Two people died after falling into the sea at Muros del Nalon and Cudillero," the emergency services from the northwestern region of Asturias said.

Firefighters used a helicopter to recover "the lifeless body of a man" in Muros del Nalon after being alerted that a person had fallen into the sea. The body of a woman was also recovered in Cudillero.

In the northeastern Catalonia region, a 32-year-old German man entered the sea to try and save a 16-year-old Moroccan boy who had fallen into the water off Tarragona beach, but both drowned, the Civil Guard told AFP.

Spain's meteorological agency, AEMET, issued an orange warning for dangerous rough seas on Thursday, citing waves of six to seven metres.

AEMET also warned that Storm Nelson, currently over Britain, would bring turbulent weather to the Iberian Peninsula until the end of March.