Video taken today by one fan shows shirtless supporters drinking beer and chanting while Spanish riot police try to disperse them.
At one point they can be heard singing, “You Spanish b*******, Gibraltar is ours.”
The British overseas territory on Spain’s southern peninsula has been a contentious subject between London and Madrid since Brexit negotiations officially began.
The footage also shows several objects being thrown as well bottles and rubbish strewn across the ground in the popular tourist square.
It comes as the English champions prepare to take on Atletico Madrid at the Vicente Calderon Stadium in the quarter finals of the prestigious European competition. Around 3,000 Leicester fans were expected to make the trip.
Late on Tuesday night, eight Leicester fans were reportedly arrested for public disorder in the same square.
Authorities said some of the club’s fans disrespected police officers and caused problems. About 100 Leicester fans were in the square when the problems occurred. Authorities said the disorder began when police officers tried to disperse the crowd.
Spanish media said two officers and three fans sustained minor injuries.