The quarterfinal games between Real Madrid and Chelsea on Tuesday and Atletico Madrid and Manchester City on Wednesday have been declared ``high-risk'' matches by the local authorities.

Added security personnel will be in place at the main Madrid squares where visiting fans usually gather before matches.

Extra attention will also be given to subway stations and the Madrid airport, where Chelsea and Man City fans may coincide while in the Spanish city.

There was some fan violence last month in the southern city of Seville when fans came from Germany and England for Europa League matches a day apart.

Madrid successfully hosted the 2019 Champions League final between English clubs Liverpool and Tottenham.

Madrid defeated Chelsea 3-1 in the first leg in London, while Man City beat Atletico 1-0 in Manchester.

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