UEFA has written to the mayors of Polish and Ukrainian cities hosting Euro 2012 training sessions to ask for an increased police presence to avoid racist behavior from fans, according to Reuters.

Some members of the Netherlands squad complained of hearing monkey noises at an open training session at Wisla Krakow's stadium last week when tens of thousands of Poles turned up to watch.

"UEFA...asks that all effective and necessary measures including an increased police presence be implemented to prevent any display of discriminatory or racist behavior at such public sessions," a UEFA statement said on Monday, June 11.

A letter was also sent to the Polish Sports Minister Joanna Mucha asking for the full support of the authorities.