Police have started an investigation into a number of assaults in Warrington following a visit by the founder of the English Defence League, Tommy Robinson.
Mr Robinson, who is standing as a candidate for the European Parliament, had a milkshake thrown over him in the town centre on Thursday.
Two people were taken to hospital in the hours that followed.
“We will not tolerate disorder… whatever the motivation,” said Ch Insp Simon Meegan of Cheshire Constabulary.
“We are aware there has been a lot of talk, videos and speculation about what happened on social media but we need to hear from people who were there at the time and witnessed what happened.
“In particular, we want to hear from anyone who was in the area at the time and recorded any of the incidents on their mobile phone,” he said.
It was the second time in two days Mr Robinson he had a milkshake thrown over him on the campaign trail.
He is running as an independent to become an MEP for the north-west England, one of eleven candidates in the constituency.
Footage posted on social media appeared to show Mr Robinson arguing with another man before a milkshake is thrown.
There is then an altercation.
Other footage showed a further altercation between a number of people in central Warrington later that afternoon.
“We will not tolerate disorder or any level of violence in Warrington, whatever the motivation,” said Ch Insp Meegan.
“This is a complex investigation, which involves a large number of people and we are treating this matter seriously and asking for the public’s help in tracing those responsible.
No arrests have been made and inquiries are ongoing, police said.