Police are yet to lay charges after more than 150 people interrupted an Aussie Rules club celebration by brawling nearby with baseball bats and poles, before being dispersed with pepper spray and resuming the fight at a nearby property.

Key points: Two major brawls in Esperance on Saturday stemmed from tensions between two families, police allege

Two major brawls in Esperance on Saturday stemmed from tensions between two families, police allege Police say the Esperance Football Club was not involved in the fighting

Police say the Esperance Football Club was not involved in the fighting Kalgoorlie police officers have come to Esperance to help with the investigation

On Saturday night, the first fight broke out near the Esperance Football Club — which was in the throes of its post-grand final celebration — before another ignited at a Sinclair property.

Michael Harding, Esperance Football Club president, was among those "gobsmacked" when people started arriving near the club gate with weapons.

"They just jumped out of cars and were running towards anyone; they didn't care who they hit," he said.

"A lot of the guys were just trying to stand by our gate and keep them out on the road so they couldn't get in.

"I've never seen nothing like it and I probably don't want to see it again. Everyone was just gobsmacked that it happened."

Senior Sergeant Justin Tarasinski alleged the fighting stemmed from a five-year feud between two families, and emphasised the football club was not involved.

As an investigation into the incident continues, he called on victims to come forward, witnesses to provide CCTV and mobile phone footage, and for the feuding family members to be calm.

"This has been ongoing for five years between these families so again, tensions have been bubbling away and those are things that we're trying to get to the bottom of," he said.

"But we need both those families on board to work with us — as opposed to against us."

'200 people in the streets fighting'

Senior Sergeant Tarasinski said police had been warned that tensions surrounding the two families might come to a head at the grand final at Gibson, north of Esperance.

"There was an incident earlier on in the week and then we received some phone calls on Friday that things might escalate, but we weren't aware of specifics.

"We'd been provided information that the football grand final might be somewhere where things might kick off, so it was better for us just to be on the front foot and have those resources available just in case."

While he called in six extra Kalgoorlie officers to patrol the football match, the fighting began long after the final siren.

Senior Sergeant Justin Tarasinski is calling on victims and witnesses to come forward with information. ( ABC News: Tom Joyner )

Senior Sergeant Tarasinski said the first brawl was near the clubhouse.

"We had one group of family attend the Esperance Football Club seeking out members of the other family that were in attendance at the post-grand final celebrations there at Esperance," he said.

"That escalated very, very quickly to the extent that there ended up being 150-odd people from both sides of the family with several weapons involved and several assaults obviously taking place.

"We had all police officers in attendance [and] there were a number of people pepper-sprayed at the scene [and] a number of people that had obviously been assaulted, some of those with weapons.

"And then unfortunately, about 45 minutes later, it kicked off again at an address down the road a little bit further and again we very quickly had another 150 to 200 people in the streets fighting."

Senior Sergeant Tarasinski said it was a difficult situation for the 18 police officers whose primary goal was to restore calm.

He said no arrests were made on the night.

"Obviously, with only having 18 up against 150 people that are very aggressive, very upset and angry and highly emotive, their role on the night was literally that — just to try and restore as much order as they possibly could," he said.

He said while the brawlers were armed with poles and baseball bats, he did not believe firearms were involved.

It is believed a number of people were taken to hospital.

'Lengthy investigation' underway

Senior Sergeant Tarasinski said a number of victims and witnesses had come forward to make statements and file reports — but he believes many more are yet to.

More officers have come from Kalgoorlie to help with the investigation and Senior Sergeant Tarasinski is confident charges will be laid shortly.

"There is a lengthy investigation to take place," he said.

"There will be a number of arrests, there will be a number of people charged in the coming days, but not as yet."