Merseyside Police say the use of pepper spray towards Leeds fans at Everton on Saturday was "proportionate and necessary" during an incident where a man was arrested for assaulting an officer.
Videos of fans being sprayed by officers emerged on social media following Everton's 3-0 Premier League win at Goodison Park.
The footage shows police attempting to hold back fans as scuffles break out, with several supporters rubbing their eyes as the spray takes effect.
Police say the incident occurred after bottles were thrown at officers and two were punched in the face as they attempted to detain a man, who was reported to have assaulted a steward.
A police statement said pepper, or PAVA, spray was "deployed in order to bring the situation under control for the safety of fans".
Graham Hyde, the vice-chair of the Leeds United Supporters Trust, disagreed that using pepper spray was proportionate and also claimed that the incident was aggravated by a steward.
"We do not wish to see anyone hurt including fans, stewards and police, and would always prefer to see the handling of fans done in a diplomatic and non-inflammatory manner," he said.
Merseyside Police said: "At around 4.05pm at the start of the second half, it was reported a steward had been headbutted by a man in the away section on the Lower Bullens stand.
"Officers attended and while attempting to detain the male, other members of the crowd began to throw bottles at officers and two officers were punched to the face.
"One man, aged 44, from Skipton, was arrested on suspicion of being drunk and disorderly and assaulting an officer. He was taken into custody to be interviewed and has been released under investigation.
"When police were assaulted, officers deployed PAVA spray in order to bring the situation under control for the safety of fans near to the disturbance.
"Efforts were made immediately after to identify anyone affected by the spray and provide them with aftercare and support.
"The use of PAVA in this incident has been reviewed by our Professional Standards Department who are satisfied that its use was proportionate and necessary.
"Enquiries into the incident are ongoing and Merseyside Police is examining CCTV and working with Everton FC and Leeds United to establish the full circumstances and identify any offenders."
Hyde said: "We don't challenge there was over-reaction from fans and bottles thrown. We don't want to see that or anyone's safety endangered."
But he added: "There always seems to be a rush to blame the fans rather than looking at the whole picture."
Everton declined to comment.