Al Qaeda is planning to attack the Euro 2008 football championships in Switzerland and Austria in June, Swiss police say.

"The Euro 2008 tournament is a target cited by the Islamist terrorist network," federal police spokesman Juerg Buehler told Swiss newspaper La Liberte.

He said messages had been posted on Islamist websites and police were "following the situation very closely".

One of the messages urges terrorists to "transform the safest countries in Europe to the hell seen in Iraq or Afghanistan".

"The time has come for the fighters of the faith. They must make their voices heard," said another.

Authorities fear the global media coverage of the tournament will make it an attractive target for an attack.

Security will be tight in and around the grounds, and extra checks will be made on people buying tickets from "high-risk" areas in the Middle East, the newspaper reported.

The federal government's security budget for the tournament is said to top £18m.