Police acting on information from the National Football Intelligence Unit arrested 10 men in raids yesterday in the north and south of England.
The arrests take to more than 30 the number of suspects held by police before Euro 96.
The Association of Chief Police Officers did not say recent operations in Newcastle and yesterday's raids in Manchester, north London and Essex had been co-ordinated, but a spokesman said most law-abiding fans would be delighted.
During the operations in north London and Essex, officers recovered weapons, including an ornamental sword, a bayonet, a flick knife, knuckle-duster and lock knife. Detectives also impounded four tickets for England's opening game, against Switzerland at Wembley, and six for the potentially volatile match against Scotland on 15 June.
Six men were arrested at several addresses. A seventh later gave himself up.
The raids, codenamed Operation Take-off, were the culmination of inquiries into violence at the Arsenal vs Tottenham Hotspur match in April. But they are regarded as preventive measures against trouble at Euro 96.
Detective Chief Inspector Dave Crompton, who led the operation, said: "We want to send out a strong message to the football hooligan fraternity - that football violence won't be tolerated and investigations will continue long after the European Championship has finished."
Police later issued pictures of six more men, captured on video during disturbances, whom they wish to interview. A "rogues' gallery" of suspects published after trouble in Newcastle last month led to more than 20 arrests.
The crackdown continued in Manchester yesterday, when police investigating the extremist right-wing group Combat 18 arrested three men in a raid on an Oldham house A spokesman said officers had been investigating the distribution of racist material and criminal damage allegations.
They seized documents and videos, aiming to establish whether the group has links with extreme-right groups on the Continent. "It is understood the men arrested have international connections, and their involvement in planned violent confrontations at Euro 96 cannot be discounted," the spokesman said.Reuse content