BARCELONA: At least 13 people were killed and over 50 injured on Thursday when a driver ploughed a van into pedestrians on a busy street in Barcelona popular with tourists, the region's interior minister said.
"We can confirm there are 13 dead and more than 50 injured," Joaquim Forn tweeted.
One suspect has been arrested, the police said.
"We arrested a man and we are treating this as a terrorist attack," police in the Spanish region of Catalonia, where Barcelona is located, tweeted. They added that no one was holed up in any bar of central Barcelona, denying what a police source had earlier said.
A local newspaper had said the driver of the white van had fled on foot after mowing down dozens of people. Some reports had earlier quoted police sources as saying the attackers are believed to be holed up in a bar.
The area around the incident was cordoned off, with several police vehicles and ambulances there; locals said they could see helicopters in the sky.
Emergency services said people should not go to the area around the city's Placa Catalunya, and requested the closure of nearby train and metro stations. The famous Las Ramblas boulevard is one of Barcelona's busiest streets, normally thronged with tourists and street performers until well into the night. Barcelona is Spain's second biggest city after its capital Madrid.
Spanish Prime Minister Mariano Rajoy said he was in contact with authorities and that the priority was to attend to the injured.
While full details of the incident were not immediately clear, since July 2016 vehicles have been used to ram into crowds in a series of militant attacks across Europe, killing well over 100 people in Nice, Berlin, London and Stockholm.
In recent weeks, threatening graffiti against tourists has appeared in Barcelona, which draws at least 11 million visitors a year.
In one video released under the slogan "tourism kills neighbourhoods", several hooded individuals stopped a tourist bus in Barcelona, slashed the tyres and spray-painted the windscreen.