The video emerged on Australian site Perth Now, which claimed women were left screaming as the trouble kicked off.
United fan Caitlin Rose claimed it started when Leeds supporters decided to move into the section housing fans of Ole Gunnar Solskjaer's side, intent on causing trouble.
"I personally wasn't scared but quite a few others were and some ladies were screaming so much for police to come as it just escalated so quickly," he said.
"Some people then left after the police came as it was near the end of the game."
Another Reds fan James Beach said his family had to endure abuse from rival fans, including regular swearing.
"He was sitting right behind us. We accept that there is rivalry between the two clubs but to go to that extent, he was very abusive," he said.
"There were so many parents there with young kids under 10, we were all shaking our heads. One friend turned around and told him to zip it and he went off his face, I was afraid for myself as well that it was going to come down to blows.
"He said 'if you don't like it you can p**s off'"
Western Australia Police confirmed there had been issues with crowd control which saw some ejected from the ground.
A statement said: "None of these incidents resulted in any criminal charges.
"A 29-year-old WA man was issued a move on notice for breaching the perimeter fence at the oval.
"He did not make it onto the actual playing area."
Leeds have travelled on to Sydney for the final match of their tour to Australia, while United have flown to Singapore where they face Inter Milan in Saturday.
