BARCELONA (AFP) - Spanish authorities said agents shot at a vehicle that forced its way through a police checkpoint in Barcelona on Thursday (Aug 17), knocking down two officers, but it was unclear whether there was any link to the deadly van rampage earlier in the city.

At least 13 people were killed and more than 50 injured when a driver deliberately slammed his vehicle into crowds on Barcelona's most popular street - Las Ramblas - in what police qualified as a "terror attack."

"In the process of closing the city of Barcelona, a vehicle forced its way through police controls and knocked down two officers," said a spokeswoman for police in Catalonia where Barcelona is located.

"Their lives are not in danger," she told AFP.

"In the incident, shots were fired to try and stop the vehicle."

Police said the vehicle was later stopped in Sant Just Desvern near Barcelona.

It was unclear whether the driver was still in it.