Officers staged the stadium's largest ever policing operation

Nine people are known to have been arrested during trouble before and after Portsmouth's 1-0 victory over Southampton at Fratton Park.

Two people, including a BBC cameraman, needed hospital treatment following the violence outside the ground.

Police officers, and their dogs, horses and vehicles were also targeted.

Two police dogs were injured in what police described as a "large scale public disorder", but a spokeswoman said there were no serious injuries.

Sadly there was a small minority who refused to leave and wanted confrontation with the away fans and police Asst Chief Con Colin Smith

Police said a device called thunderflash, which explodes on contact, and two bottles of ammonia were found before the match.

More than 400 officers were involved in the operation, the force said.

Sunday's game was the third time the rival clubs have played each other this season, with Southampton winning the first two matches.

Portsmouth's victory was the first time the club has beaten Southampton at home for 41 years.

Chief Superintendent Dan Clacher said: "It is extremely disappointing a very small vocal minority chose to attack police and visiting supporters and attempted to spoil this much anticipated event for everybody.

"Many offenders have been caught on camera and we will be using all evidence collated as part of a major inquiry into the incidents of violence.

'Family atmosphere'

"We will put every effort into identifying and locating those responsible and bringing them to justice."

Assistant Chief Constable Colin Smith said: "This was a hard-fought footballing contest which was enjoyed by many people.

"Sadly there was a small minority who refused to leave and wanted confrontation with the away fans and police.

"This was pure irresponsible stupidity by people who do not support the club."

He said the club tried to create a "family atmosphere" for all games.