Police had last night arrested 17 football hooligans after more than 20 officers were injured in violent clashes following Sunday's Birmingham derby at St Andrew's.

Rival fans were caught up in a spate of fights with each other and against police after Aston Villa beat Birmingham City 1-2 away.

An investigation into the post-match riots is ongoing, and West Midlands Police are scour-ing CCTV footage for further clues.

Several police vehicles were also damaged in the fighting.

Violence had flared outside the ground, in Bordesley Green and continued up to St Martin's in the Bullring.

Trouble also erupted in Edgbaston Street, at the back of the Bullring shopping centre, 90 minutes after the final whistle.

One Aston Villa supporter claimed trouble flared after the away fans came under attack as they were marched through Digbeth into the city centre by police.

More than 20 officers were assaulted trying to quell the violence. Police said they suffered minor injuries.

A number of police vehicles were also damaged, including a several riot vans being smashed up outside the ground.

Six people, aged between 16 and 25, were arrested on Sunday on suspicion of football-related disorder, but further arrests brought the tally up to 17.

Acting Det Chief Insp Paul Ford, of Steel-house Lane police station, said: "It was very disappointing behaviour from a small minority of so-called fans.

"There were a total of 28,000 people who attended the match but there was a small element of people who tried to spoil the reputation of two excellent football clubs - they are not real fans."

Earlier, Villa fans claimed they were left like 'sitting ducks' after being targeted by rival fans throwing bricks and bottles as police kept them in a car park at the ground for more than an hour.

One Villa fan from Sutton Coldfield, who did not want to be named, said: "There were about 2,000 of us penned in after the game for about an hour.

"Blues fans were rattling the gates and throwing things at us over the barriers.

"It was complete mayhem and everyone was doing their best to look after each other. It was really intimidating.

"The police were supposed to be escorting us but in the end we got split up and some of us had to hide."

Another fan, at the game with his 14-year-old son, said: "The police forced the Villa fans to walk into the city centre. It made us a target.

"I was frightened. I don't expect to have to take my son into an environment where I'm worried about my own safety let alone his. I will be writing to police about this."

Ambulance crews reported that nobody had been seriously injured immediately after the game but there had been a number of isolated incidents. Detectives were yesterday recovering footage from CCTV cameras outside the ground and through Digbeth in the hunt for evidence of those involved in trouble.

Acting Chief Insp Ford added: "We have a duty of care to make sure fans are kept safe. We kept opposing supporters separated to stop them attacking each other."

A spokesman for Birmingham City Football Club said: "Derby games can have quite a reputation but we were happy the game went off without any major incidents inside the stadium.

"We heard of no major incidents after the game either so, as an event, it was successful from the club's point of view."

West Midlands Police appealed for witnesses or anyone with information to contact 0845 113 5000.