But Mr van der Veen dismissed fans’ claims of strong arm tactics, saying: “We don’t attack people. What we do is focus on a person who has to be arrested.
“Two officers in plain clothes will get hold of the guy, and a few other officers make a sort of ring round them to make sure they can do their work and take out the person that has to be arrested.
“If there is any violence or threat of violence in the direction of these officers, then of course we don’t ask, ‘Could you stop that?’
“We do not walk towards someone and say, ‘Hey, hello, we are from the police. You are being arrested, could you walk with us please?”
Mr van der Veen said police were pelted with bottles by Celtic fans. He added: “We see that as a crime.
“Some people were arrested, then a group started to attack the officers in plain clothes. During that period, a lot of bottles were thrown by Celtic fans.”