The number of foreign visitors to Spain plunged during the first nine months of the year, official data showed Tuesday, with the pandemic freezing a once-booming tourism sector.

Between January and September 16.8 million foreigners arrived in Spain, the world's second-most visited country, a drop of around 75 percent over the same time last year, national statistics institute INE said.

Spain, one of the hardest-hit countries in Europe by the pandemic, imposed a strict nationwide lockdown in March that was only fully lifted in late June and paralyzed its key tourism sector. Like other European Union nations, Spain in March closed its borders to all non-essential travel.

Tourist chiefs had hoped the sector would improve in the summer but those homes were dashed when Britain on July 25 ordered a two-week quarantine for anyone arriving from Spain due to a rise in infections.

Britain has long been Spain's biggest source of foreign tourists and the measure sparked a wave of holiday cancellations by Britons.

International tourist arrivals to Spain fell 87 percent in September over the same month last year as new virus restrictions came into place to deal with a second wave of infections. That is a steeper fall than the 76 percent recorded in August.

France now accounts for the largest group of foreign tourist arrivals after the number of Britons plunged 81 percent during the first nine months of the year.

Spain in 2019 hit a record for the seventh year in a row, welcoming a total of 83.7 million foreign tourists. Only France received more that year.

Tourism accounts for some 12 percent of GDP and 13 percent of employment in Spain and the plunge in arrivals has hit the economy, the eurozone's fourth biggest, hard.