The protester, who was dressed in black, was hit by a tear gas canister from police as he tried to enter the police station.
The video, which was uploaded to Facebook, shows a group of protesters being escorted to the entrance of the station by security forces, with their hands on their heads. As the protest is taking place, the crowd chants slogans in Catalan and English towards security personnel.
Spanish newspaper El Mundo reported that the protester’s leg was cut above the knee and he was taken to hospital for treatment.
A spokesman for the police in Barcelona said: “The police used their normal tools and tactics as a result.
“We do not allow any form of violence at the protest as it is contrary to the legal order and has caused problems for the entire police station.”
Demonstrators also occupied a police station in the Catalan city of Girona, according to Reuters news agency.