The Germany Interior Minister, Mr Manfred Kanther, called yesterday for tougher measures against football hooligans following the violent scenes surrounding Germany's World Cup match against Yugoslavia in the French city of Lens.
The violence, which left a French policeman in a coma, was condemned by members of all parties during a Bundestag debate.
Mr Kanther said he hoped police action against hooligans could be improved but he acknowledged that it is often difficult to identify troublemakers before they leave the country.
Border guards turned back a number of football fans attempting to cross into France near Saabruecken yesterday after they found hammers, knives and baseball bats in their luggage.
Police in Munich arrested three people yesterday following a search of 20 houses occupied by suspected right-wing extremists. During the search, which involved 300 police officers, they discovered machine guns, ammunition, hand grenades and land mines, as well as banned, neo-Nazi propaganda.
One of two Germans who have been held by French police in connection with Sunday's attack has been identified as Mr Markus Warneke (27) from the northern city of Hanover. A doctor's son who runs a tattoo studio in the city, he is known to police as a violent hooligan but is not believed to be a member of the far-right, skinhead scene.
"We place him in Category C, the hard core of violent hooligans," said Mr Ingo Marek, an interior ministry spokesman.
Police in Sarstedt, where Warneke grew up in leafy comfort, said he has often been in trouble but was essentially a pleasant, quiet person.
"He just snaps when he hears the word football and he is with his friends," said a local policeman, Mr Klaus Kronhard.
Mr Warneke's tattoo studio was attacked earlier this week, leaving windows and a sign smashed.
German investigators have discovered a neo-Nazi Internet website with a message placed last week calling on hooligans to create as much trouble as possible in France.
According to Dr Gunter Pilz, a sociologist at Hanover University who studies the link between violence and football, the scenes in Lens on Sunday represent a new form of hooligans.
"The criminals of Lens were neither disappointed football fans nor were they drunk like the English. They were armed like hooligans but they belonged to a group that has caused us ever greater worries in the past two or three years - the extreme right," he said.
Dr Pilz believes that the shocking consequences of Sunday's violence could give some hooligans pause but it was unlikely to affect neo-Nazis.
"One cannot guarantee anything where the extreme rightists are concerned. A human life is not worth much to them," he said.
An Austrian eyewitness to the attack on a French policeman in Lens has been held for questioning. The 17-year-old, identified only as Walter S from Vienna, was detained at the Stade de France outside Paris and is suspected of having sold pictures of Sunday's attack to a German newspaper.
