A Leyland supermarket was forced to close early and several youths were arrested after Bonfire Night fun descended into violence.
Problems erupted after thousands of people had enjoyed the Leyland Round Table firework show at Worden Park.
The event passed off without major incident but the police were called after youths started congregating afterwards outside Tesco in Towngate.
The store has been the scene of anti-social behaviour in the past and the police were called after youngsters started letting off fireworks.
The problem then moved to McDonalds, in Churchill Way, where staff recently beefed up security because of complaints about hoodies.
Trouble flared a little before midnight and police were called.
A total of five people were arrested on suspicion of public disorder offences and assault. Chief Supt Richard Robertshaw said it was a disappointing end to an otherwise good night.
He said: “The bonfire at Worden Park was really well organised by Leyland Round Table and passed off without incident.
“However, unfortunately a small minority of youths who attended were intent on causing trouble.
“It started at Tesco and moved to the car park at McDonalds.
“There were additional staff on duty in Leyland and they were deployed swiftly.
“A number of youths have been arrested.”
A spokesperson for Tesco told the Leyland Guardian: “There was an incident on Saturday night involving youths who were messing about in the car park.
“A number of fireworks were let off, but we’re not sure how many. On the advice of the police we closed the store early.”
The spokesperson said that customers were prevented from entering the store but that it was not necessary to have an emergency evacuation. No damage or injuries were reported.
The store, which is normally open until midnight, closed at 9.30pm.
Nobody from McDonalds was available to comment.