Polish police yesterday announced they had arrested 21 people in a crackdown on football hooligans, in the wake of trouble that marred the Euro 2012 host nation’s cup final last week.

“They were identified thanks to surveillance recordings. The evidence has enabled them to be charged with destruction of property, invading the pitch and attacking security forces, including the police,” Poland’s police chief Andrzej Matejuk was quoted as saying.

Police said that more arrests were on the cards, because they had identified 70 individuals involved in the cup final fracas in the northern city of Bydgoszcz on May 3.

The game pitted high-flying sides Lech Poznan and Legia Warsaw. After it ended 1-1, Legia went on to win 5-4 on penalties and supporters of both sides invaded the pitch, forcing the police to step in.

They also smashed up seats and other stadium equipment.

There is no love lost between fans from the western city of Poznan and those from the Polish capital Warsaw, and hardcore supporters of both Lech and Legia have earned a reputation for making trouble.

After the cup final trouble, Polish authorities ordered Lech and Legia to play their next home matches in empty grounds.

That sparked a street protest by some 3,000 Legia fans outside their stadium on Friday, some of whom wore masks and threatened television crews and news ­photographers.

Inside, Legia beat league stragglers Korona Kielce 3-1.

Last month, government an-nounced a new legal crackdown, with a raft of measures to be in place in time for Euro 2012.

A key plank is fast-track handling of troublemakers, with special rooms being set up in various stadiums with video links to courthouses from which judges will try the defendants.