Polish prosecutors are investigating violence by Polish hooligans against Lithuanian police around last week's friendly and say offenders could face up to five years in prison.
Polish fans clashed with police in Kaunas, Lithuania, during Friday's friendly - which Poland lost 2-0. Around 60 Poles were detained for throwing bottles, flares and benches at police and security guards. One guard was injured.
A spokeswoman for Warsaw prosecutors, Monika Lewandowska, says on Tuesday that prosecutors have opened an investigation. Any sentences will be served in Poland.
The probe comes as Polish authorities vow zero tolerance toward football violence as they prepare to co-host Euro 2012.
Prime Minister Donald Tusk called on Monday for strict punishments for ''thugs.''
