Norwich City supporters have received an apology from police after an internal investigation examined disturbances before the Canaries’ triumphant away win over rivals Ipswich Town last season.

Up to 400 City fans, many of them women and children, missed the first goal of the 5-1 victory on April 21 because of a large presence of rival fans and pockets of disorder stretching police resources outside Portman Road.

Ipswich fans had tried to break through police lines to reach Canaries’ supporters and threw objects at them as police were forced to draw batons to keep the rival factions apart.

Suffolk police released the results of an internal investigation and apologised to the 2,125 Norwich fans who attended for problems they had encountered on the derby night.

The report recommends Suffolk police should deploy larger numbers of specially trained officers at derby games to prevent future public disorder.

After the trouble, Norwich City and fans complained to Suffolk police about the way it handled the policing of the game.

The report praised officers for their courage and professionalism as they were “subjected to danger themselves” before the game. Suffolk police also praised the majority of both set of fans for their impeccable behaviour on the night.

A Suffolk police spokesman said: “The force apologises for confusion caused to some Norwich City fans after officers made a genuine mistake of advising them of an apparent delayed kick-off.

“Suffolk Police also states that it must take its share of responsibility for the congestion on the routes outside the ground.

“Officer numbers were stretched during the evening as a result of pockets of disorder around Ipswich, especially on Portman Road where the presence of Ipswich Town fans prohibited approximately 400 away fans from entering the ground in time for kick-off.”

CCTV coverage showed many of the fans consisted of families, women and children.

The internal investigation did not cover trouble after the game where Canaries fans were said to be prevented from entering Ipswich railway station by angry home fans. At least six arrests were made on the night.

Robin Sainty, chairman of the Norwich City Independent Supporters’ Association, had attended the game. Describing the police response, Mr Sainty said: “They were making ad hoc decisions. Their plan, if they even had one in the first place, had not worked.”

A Norwich City spokesman said: “It is good to see the police have identified areas for improvement for handling any future derby games and that they have apologised to our supporters for giving misleading information on the day that kick-off had been delayed. We hope the lessons learned will lead to an improved experience for our supporters attending any future games at Portman Road.”