TROUBLEMAKERS have been warned to stay away from tomorrow's clash between Lancashire rivals Burnley and Blackpool.

Up to 4,000 Seasiders fans are expected to make the 50-mile trip from the coast for the game but officers are warning troublemakers to stay away.

The fixture is the first derby the Tangerines have been involved in since promotion to the Championship in May.

Police in the resort have sent 25 letters to suspected thugs in an attempt to keep them from the game, although posts on internet message boards say they still intend to turn up at Turf Moor.

To try and keep trouble to a minimum the Blackpool fans will be kept inside Turf Moor for ten minutes after the final whistle to let the Clarets fans disperse.

Police spotters will also be amongst the fans in a bid to identify known troublemakers.

Match Commander Chief Insp Jeff Brown, of Burnley police, said: "The majority of fans come to watch football in a perfectly law-abiding way.

"It is an exciting time for both clubs because they are doing well and have some investment going in, but the reality is that a small number of individuals will look to exploit every opportunity they can to cause trouble and my view as match commander is that they will be dealt with firmly."

Insp David Old of Blackpool Police said: "There have been letters sent out and those who have received them have got them for a reason.

"They have been sent out as a deterrent to people who we have had problems with in the past for organising trouble or being involved in trouble."

In 1997, 13 fans were arrested before a game at Bloomfield Road, charged with attempting to get into the ground while drunk and possessing weapons.

Burnley fans were also ejected from the ground after throwing coins at home fans.

Currently 70 Burnley fans are banned from football grounds.