NYON, Switzerland (AP)After hundreds of Inter Milan fans with tickets were denied entry to a Champions League game at Porto, UEFA said Wednesday it will look into the incident and the Italian club promised a formal complaint.

Inter chief executive Beppe Marotta said in a post-game interview late Tuesday that children were crying outside the stadium after they were not allowed in to see their team draw 0-0 and advance to the quarterfinals.

In a statement Wednesday, Inter said its fans were exposed to “serious tension and potential danger.”

“A large number of Inter supporters, including many families with children, were segregated in a containment area near the visitors’ section and held there for the duration of the match, which they were unable to watch,” the club said.

The incident flared in Portugal in the same week officials in Italy denied entry for German fans wanting to see the Napoli-Eintracht Frankfurt game on Wednesday in the Champions League round of 16.

Host clubs and city authorities are responsible for stadium security and UEFA suggested the issue was that some Inter fans had tickets to sit in sections reserved for Porto supporters.

“UEFA had been made aware that a large contingent of visiting supporters have procured tickets in home sectors of the stadium,” the European soccer body said in a statement.

Champions League regulations require home clubs to allocate 5% of stadium capacity for away teams, which Porto seemed to have complied with.

Inter fans had traveled in large numbers to see their team try to reach the quarterfinals for the first time since 2011 at the Porto stadium, which hosted the final two years ago.

“Mitigation measures were discussed between both clubs,” said UEFA, which has a match delegate on site for each game it organizes to liaise with team and city officials. “UEFA is currently looking into the matter.”

Inter urged UEFA to intervene “so that light is shed on what happened and that situations of this kind, contrary to the key principles of sportsmanship, equality and inclusion, are never repeated, in defense of all fans, regardless of their football faith and nationality.” —

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