Two Paris Saint-Germain supporters suffered knife wounds in two separate incidents following the French side's Champions League match on Wednesday against Barcelona in the Spanish city, police said.
The two victims, whose lives were not in danger, were taken to hospital for treatment, a police spokesman said, adding that the identity of their attackers was not known. One of the two victims remained in hospital.
The attacks come less than two weeks after a Deportivo fan was killed after being beaten and pushed into a river during clashes outside Atletico Madrid's Vicente Calderon stadium before a La Liga match between the two sides.
The Spanish government sacked the security heads of the two clubs after the death and Spain's Football Federation and the government-controlled Higher Sports Council have said tougher sanctions for clubs over violent behaviour by supporters will come into force on December 15.
Barcelona won the match 3-1 but both sides qualified for the last 16 knockout stages of the competition.
Source: AFP