Spanish police used gunfire in an attempt to stop the driver of a stolen truck laden with household gas canisters who was heading in the wrong direction near the city centre on Barcelona's main ring road.
Police shot at the lorry's windscreen after a high-speed chase during which some of the gas containers had fallen off the trailer, with one person reported injured by a falling canister.
In total the police said they fired seven times at the lorry, as well as warning shots in the air, but the driver did not stop. At one point, a policeman had to jump out of the way.
"He was driving forward obsessively but he did not aim at pedestrians," a police spokesperson said.
The chase ended after three kilometres when the driver, identified by police sources as a Swedish citizen, was forced to stop by the flow of traffic after he had taken a slip road heading in the wrong direction. The slipway leads to a tunnel on Barcelona's Litoral ring road.
The Spanish government said the incident was not terror-related.
Spain's interior minister, Juan Ignacio Zoido, tweeted: "The arrested driver of the stolen gas truck in Barcelona has a record of psychiatric problems. It was not a terrorist act".
Police have said that the suspect had stolen the vehicle near the central Drassanes square area close to Barcelona's old port, while the driver was making deliveries of butane gas.
Witnesses say he sped northwards through the old port area, ignoring signals to stop from motorcycle police and smashing into cars that were in the lorry's path.
Fourteen gas canisters toppled off the lorry at one point as the driver swerved across the road at high speed.
The driver is said to have escaped injury but was taken to a hospital owing to concerns over his mental state.
The Barcelona newspaper La Vanguardia quotes police sources as saying that the suspect may have been under the influence of drugs.
A police spokesperson said that they had not been able to interrogate the suspect as he said he could not understand Spanish, Catalan or English.
The man had arrived recently in Barcelona, but police were still investigating where he had been staying.
One eye witness was impressed by the speedy reaction of the police to the security threat.
"We heard sirens and then a very loud noise. We looked out and saw how the butane truck braked suddenly in the highway entrance. It was going in the wrong direction," Jordi Sintes, an employee from the nearby Hospital del Mar Medical Research Institute, told La Vanguardia.
"Two motorcycles from the [local police] Guardia Urbana were following him. They dismounted and aimed their handguns at the driver.
"He spread his arms and straightaway three Mossos [Catalonia police force] tackled him.
"In a question of minutes police appeared from all directions, some with machine guns. In five minutes they led him away in handcuffs."
- Originally published in Telegraph UK