UEFA have issued a press release confirming that they’re looking into the incident which saw hundreds of Inter fans barred entry into Porto’s stadium yesterday, stating that they have been informed that many fans held tickets in the home section.

The organization’s press release, as reported by FCInterNews, outlines the official policy around travelling supporters in away matches in UEFA competitions, and suggests that travelling supporters holding tickets not in the designated away end could be at the root of the issue yesterday.

What is clear is that yesterday there was a significant number of travelling Inter fans who showed up to the Estadio do Dragao for their team’s Champions League round of sixteen second leg against Porto but were unable to enter the stadium, causing no small amount of chaos.

What is not clear is exactly what led to this organizational breakdown.

One cause that has been suggested in initial reports is that some fans who held tickets in sections of the stadium that they were not meant to be in were turned away, and this is further suggested by UEFA’s initial press release on the matter.

“UEFA have been informed that a large number of away fans bought tickets in the home section of the stadium,” the organization’s press release reads.

“UEFA regulations establish that at least 5% of a stadium capacity must be provided to the visiting team in an area reserved for their fans,” it continues.

“The responsibility for the safe and secure handling of spectators and related ticketing policy belongs to the match organizer and to the relevant authorities.”

“Mitigation measures had been discussed between the two clubs.”

The press release concludes that “UEFA is currently looking into the matter.”