Another young man was treated for a broken jaw after being hit with a cricket stump.

Describing crowd behaviour at Monday's Skyshow fireworks as among the worst of the event's 20-year history, police and ambulance officers said alcohol-fuelled fights began in the afternoon and culminated in a mass brawl on the South Perth foreshore just before the 8pm fireworks. The violence continued in the area until after 11pm.

The 650 officers assigned to police the 300,000 people lining the city's foreshore struggled to control the mostly adult troublemakers. By the end of the night, 54 people had been taken to hospital, 22 had been arrested and more than 800 cautioned or fined for drinking in public.

The officer in charge of the event, Acting Superintendent John Gillespie, said the night had proved a "wake-up call".

He said it was clear the police and the Government had to devise new laws which would allow for designated licensed areas at such events and give officers the authority to search eskies and bags.

"Under current legislation, we are able to seize liquor from juveniles. However, we cannot seize any liquor from adults unless the bottle or can is open and about to be drunk," Superintendent Gillespie said.

Acting Premier Eric Ripper indicated the Government would consider introducing laws to boost police enforcement powers. "The majority of people attending the Skyshow behaved properly ... but a minority behaved in an appalling manner," he said.

"You can't have this drunken behaviour threatening the safety of family groups."

He conceded Skyshow might have to be cancelled if violence marred future Australia Day celebrations, but said the Government would be reluctant to take such action.

"We turn out the largest Australia Day crowd of any city in the country and we should be proud of that," he said.

Assistant Police Commissioner Wayne Gregson said the Skyshow organisers may have to restrict events leading up to the 8pm fireworks to deter crowds gathering at the foreshore early in the day.