Several arrests were made after disorder broke out at the end of the Leeds Festival on Sunday, West Yorkshire Police have said.
The Foo Fighters concluded events on the main stage at Leeds
According to a spokesman, "sporadic outbreaks of low-level disorder" occurred after the bands finished playing at Bramham Park near Wetherby.
The trouble, which included lighting fires, was mainly dealt with by the organisers' security staff.
But later a number of arrests were made by police, mostly for assault.
Around 57,000 people attended the three-day event which was being held at the private estate near Wetherby for the third time.
Until Sunday night, there had been no reports of any trouble.
Previous Leeds Festivals held at Temple Newsham in east Leeds were marred by toilets being set on fire at the end of the performances.
Artists appearing on Sunday included Kings of Leon, Razorlight and Babyshambles with proceedings brought to a close by the Foo Fighters.