A NON-league football club has vowed to ban supporters convicted of marring a key match by throwing flares on the pitch and into the crowd.

Police said disorder, which appeared to have been pre-planned, escalated as FC United of Manchester scored four goals against Whitby Town FC in an EvoStik League Premier Division fixture.

An 18-year-old local man was arrested over the incident and detectives are working to identify other people involved in the trouble, which is believed to have included violence after the match.

Seasiders' fans were seen throwing the fireworks, which let off blue smoke, on to the side of the pitch and into groups of their own supporters as FC United, a team formed in 2005 by disgruntled Manchester United followers, virtually sealed the league title.

The result also consigned Whitby Town to battling to remain above the relegation zone.

Police believe the fireworks were hidden inside the Turnbull Ground before the fixture, as the crowd of 810 - more than double the club's average attendance - was searched at the turnstiles.

Supporter Jon Stokoe said Whitby Town followers had been warned about setting off smoke bombs earlier this season and the latest incident followed tensions between the teams' fans at previous matches, with FC United fans setting light to Seasiders' flags.

He said while the flares let off an unpleasant smell and there was "a bit of fisticuffs" afterwards, it did not compare to the scenes at some European clubs, such as Galatasaray.

Mr Stokoe said: "The actions of a few idiots spoilt what was otherwise a good natured night, with both sets of fans singing.

"It is a community club with a proud history and tradition and this damages the club and the town.

"A lot of people work behind the scenes to encourage people to go along, so this is a shame."

Whitby Town chairman Graham Manser said while the behaviour of FC United fans had been exemplary, the actions of a small minority of the home fans had been "totally out of order" and any that were convicted of the disorder would be banned from the ground.

He said: "The club will not stand for it.

"In 25 to 30 years, we have never had this sort of behaviour before."

Andy Walker, of FC United, said the club had been well received at Whitby and would return in the summer for a friendly.

Anyone who witnessed, filmed or photographed the disorder should call police on 101 or email rebecca.lalor@northyorkshire.pnn.police.uk