A British brother and sister, aged 11 and 13, have died after drowning off the coast of Salou in north-eastern Spain, local authorities have confirmed.

The children were swimming at Llarga Beach in Tarragona on Tuesday evening when the tragedy occurred. Emergency services responded swiftly and managed to pull the siblings and their father from the water. Despite extensive resuscitation efforts, the two children could not be saved.

José Luis Gargallo, head of the local police force, described the incident as “deeply tragic”, adding that the father, though rescued, was found to be exhausted and had ingested a significant amount of seawater.

Earlier reports had incorrectly stated that both victims were boys. Authorities later confirmed the victims were a boy and a girl.

According to Mr Gargallo, sea conditions were unusually rough on the day of the incident, despite the beach typically being considered safe for swimmers. A yellow flag – indicating moderate hazard – had been flying throughout the day.

“This beach is normally very calm and family-friendly,” he said. “But yesterday the entire coastline was experiencing unusual turbulence. Many people underestimate the sea’s strength when it appears benign.”

Lifeguard services had concluded for the day when the distress call was made shortly before 21:00 local time.

The family, visiting from the UK, was staying at a nearby hotel. The children’s mother and other siblings were not present at the beach during the incident. Support services, including psychologists, have been provided to assist the family in the aftermath.

On Wednesday, local residents and officials gathered outside Salou town hall for a minute’s silence in memory of the young lives lost.

In a separate but equally tragic incident, a 54-year-old German man also drowned on Tuesday at Cap de Sant Pere beach in Cambrils, just a few miles from Salou.

The deaths have brought the number of beach-related fatalities in Catalonia this summer to 16 — five more than during the same period last year.

The UK Foreign Office issued a statement saying: “We are supporting the family of two British children who have died in Spain and are in contact with the local authorities.”

Salou, a popular holiday destination among British tourists, receives an estimated 1.3 million visitors from the UK each year. This latest tragedy follows a spate of fatal incidents involving British nationals in Spain this summer.

In light of recent events, Spain’s civil protection agency has renewed calls for swimmers to exercise extreme caution in coastal and inland waters throughout the summer months.