A-League shutdown risked if flares lit

Flares can easily explode and cause serious injuries, say Victoria police, who add they will shut down A-League games if fans light them.

Troublemaking Western Sydney Wanderers fans ripped 25 flares and set off detonators inside Etihad Stadium during last Saturday's clash with Melbourne Victory.

A police spokeswoman told AAP fuses in pyrotechnics burned inconsistently and could easily explode in seconds - causing serious burns and injuries.

"If allowed to explode close to the body they could do serious harm and several were thrown (last Saturday) which is of course extremely dangerous," Leading Senior Constable Julie-Anne Newman said.

Police had not seen such hooliganism in Victoria "for a long time and don't want to see them again".

Assistant Commissioner Stephen Leane said police could not allow an event with a crowd of 30,000 people to go ahead if flares and detonators were taken into stadiums.

"The response may very well be that we will have to stop the game until we can be satisfied that the place is safe," he told the Herald Sun.

The Western Sydney Wanderers were fined $50,000 and given a 12-month, three-point suspended sentence for last Saturday's hooligan behaviour.