Warsaw: Football fans experienced delays on Tuesday as UEFA launched ticket sales for Euro 2012 and the website went down due to heavy traffic.
Fans were able to register to purchase a ticket, but they were unable to chose which matches they wanted to attend.
"There are currently too many people trying to access the UEFA EURO 2012 ticket portal," the website said when users attempted to register.
A spokesman for UEFA in Poland said the technical glitch was caused by heavy traffic after thousands accessed the website when UEFA launched the ticket selection option at midnight. The website would be available at 1500 GMT.
Organisers said fans had until March 31 to select which matches they wanted to attend. They appealed for fans to not rush all at once as a lottery would be conducted if demand exceeded supply for a particular match and category.
Poland is co-hosting the tournament with Ukraine.