Police in riot gear used dogs to control the supporters
Seven people were arrested after trouble flared during Manchester United's 2-0 Carling Cup win at Barnsley on Tuesday.
Police were hit with bottles and eight catering staff were forced to hide in a store room when fans broke into their kiosk and stole food and money.
The catering firm said United fans had been upset they were not allowed to buy alcohol from the kiosk.
South Yorkshire Police said seven fans were arrested at the Oakwell Stadium.
The Football Association (FA) is investigating the incidents.
One police officer suffered a minor facial injury during the disorder.
A spokesman for South Yorkshire Police said trouble broke out at about 2030 GMT.
Officers used police dogs to try to restore order in the North Stand and drive fans back from the pitch.
Catering staff barricaded themselves in a store room for about 25 minutes when their food stand was attacked.
Jan Framp, area manager for Lindley Catering, said the attack happened after police had told catering staff not to sell alcohol at half time.
She said: "That's what upset them. They kicked the doors in and then ransacked the beer bar.
"They have ripped the water boilers off the counters, they have trashed everything."
Mrs Framp said the incident was "extremely frightening" for her staff.
Stewards on the pitch also had food thrown at them and several fans ran on to the pitch towards the end of the fourth-round game.
Four of the seven people arrested at the ground were Manchester United supporters and three were from Barnsley, police said.
Money and food were stolen from a kiosk during the game
A spokesman for Barnsley Football Club said: "[The club] has today launched a full investigation into the disturbances during last night's Carling Cup game against Manchester United at Oakwell.
"The club are working closely with South Yorkshire Police and any persons found to be involved can expect a lifetime ban from Oakwell Stadium."
Manchester United condemned the actions of their supporters who were involved in the disorder.
A spokesman said they supported the strongest possible action being taken against those who damaged the club's name, including the imposition of banning orders and the cancellation of season tickets.
The FA said they were awaiting the reports of one of their crowd control advisors who was present at the game as well as from referee Chris Foy.
The governing body are also liaising with both clubs and South Yorkshire Police to gather evidence.
CCTV images show police moving crowds back in the Oakwell Stadium