British police travelling with fans at Euro 2012 said Monday their biggest concern was foreign supporters wearing English team shirts potentially causing trouble at the tournament.

A total of 14 British police officers have been deployed in the eastern Ukrainian city of Donetsk ahead of England’s opening Group D game against France at the Donbass Arena later Monday.

An estimated 3,000 England fans bought tickets through official channels but several thousand more are expected to have headed to Ukraine independently.

However assistant chief constable Andy Holt, who is heading the British police delegation tasked with monitoring England’s supporters, said one of the biggest potential headaches was non-English fans wearing England kit.

“We have worked very hard to make sure that England fans are policed appropriately and if England fans do engage in disorder that we know about it and are able to deal with that,” he told reporters.

“But what I don’t want to do is have England fans mislabelled, and mis-identified because it’s some other nationality wearing England shirts.

“So you can imagine we will be very careful to ensure that if there are any problems, we identify the provenance of who we are dealing with.”

As Holt spoke to a small huddle of journalists outside the Donbass Arena, a group of Russian supporters wearing England shirts and brandishing a Union Jack could be seen strolling past.

Asked by an AFP reporter why they were supporting England, one fan simply pointed to a tattoo on his leg of Manchester United’s club emblem.