There were no reports of trouble among Stoke fans

Officers say they believe Birminghan City supporters staying in the Somerset town ahead of Sunday's big game were responsible for the violence.

The West Midlands club beat Norwich City in a penalty shoot-out at the Millennium Stadium to win promotion to the Premiership.

On Saturday Stoke City triumphed over both Brentford and the Millennium Stadium "jinx" to win the Division Two play off.

Bar brawls

Avon and Somerset Police said the violence erupted in the seaside resort of Weston-super-Mare at about 2230 BST on Saturday.

It was some of the worst they had dealt with in some time, said a spokesman.

One officer was knocked unconscious when he was struck by a flying bottle and had to be treated in hospital.

The trouble flared when a large number of people became involved in a fight in a bar.

Stoke's last visit to Cardiff led to violence

Officers from five other districts were call in to help control the fighting - which continued sporadically during the night until 0330 BST on Sunday.

Police said two people were being held in custody- one for assaulting a police officer and the other for public order offences.

In Cardiff, South Wales Police maintained a high profile approach ahead of the weekend's soccer play-offs.

However, the decision to bring forward Saturday's game between Stoke and Brentford appeared to have paid dividends.

Police said afterwards there had been few problems with just one arrest before the game for criminal damage.

There were concerns that some Cardiff City supporters may have targeted visiting Stoke fans following the Midland team's shock victory over the Bluebirds in the play-off semi-final at Ninian Park.

Around 600 angry Cardiff fans were involved in clashes with riot police following the match.

Five people were arrested following the violence at Ninian Park on Wednesday 1 May and police are studying CCTV footage to identify other suspects.

Small minority

The play-off semi-final was not the first match between the two sides to be marred by violence.

Clashes at a game at Stoke's Britannia Stadium in April 2000 left 12 police officers and 27 members of the public injured.

Senior officers said there was intelligence to suggest that a small minority of hooligans were intending to cause trouble on Saturday.

But Superintendent Kevin Tumelty, the man in charge of policing the Millennium Stadium play-offs, said the force was ready for any eventuality.

"Obviously we're aware that we have hooligans who are associated with Cardiff City," he said.

"We're quite satisfied that we know the identity of those individuals, and we will be looking to deal with them very firmly if they come into the city centre looking for confrontation."