Six Celtic fans have been arrested by Spanish police during a night of violence in Valencia.

Officers were seen firing rubber bullets at visiting supporters and using their batons on pub-goers.

Up to 10,000 travelling supporters are expected in the city for tonight's Europa League match with Valencia.

A spokeswoman for the National Police said six Celtic fans were arrested on Wednesday night.

They allegedly threw furniture, rubbish and glasses at police officers, while one is accused of possessing drugs.

She said: "We have six people under arrest, five of them for public disturbance."

She said a police car had been damaged in one incident and fans had gone into a bus stop and refused to move on.

The spokeswoman added: "One person has been arrested for drugs offences. He was coming by train from Castillon to Valencia with other supporters, who were causing trouble on the train.

"When officers arrived, they found this man with cocaine and crystal meth.

"I expect they will be going before a judge today. I don't know if they will be sent to prison."

One fan took to social media, saying: "Some appalling footage appearing tonight, showing Spanish police violently attacking supporters without provocation in Valencia.

"We urge all fans to stay safe and, if necessary, to document any abuses, especially if arrests are made."

Before the trouble erupted, Celtic had appealed to supporters to stay away from the stadium if they did not have a ticket.

Club security chief Ronnie Hawthorn said: "The message from the club is that only those with tickets should try to approach the stadium.

"If you have got a ticket, great. Enjoy what should be a fabulous experience. But if you don't have a ticket, watch it in a bar instead.

"It is a common-sense approach, one that Valencia and the Foreign Office have issued as well."