Cooler weather has brought brief relief for firefighters still battling bush fires in southeastern Australia.

Four major blazes are continuing to rage in the state of Victoria, where 210 people were killed in a devastating firestorm on 7 February.

But officials are warning hot weather with strong winds will increase the fire threat early next week.

In a separate development, police say they believe one of the fires on Friday was started deliberately.

Some 50 firefighters were needed to control the blaze at Arthur's Seat – a popular tourist destination east of the state capital, Melbourne.

One man has already been charged in connection with one of the fires earlier this month in the Gippsland region, which killed more than 20 people.

Victoria officials said milder weather had given firefighters much-needed reprieve.

"It provided us a good opportunity to keep building and strengthening containment lines in those existing fires," Lee Miezis, a spokes­man from Australia's Department of Sustainability and Environment, said.

But he warned the crews must prepare for dangerous weather which is forecast for next week.

"Tuesday is predicted to be very warm... with strong to gale-force north to northwesterly winds," he said.

Earlier, more than 200 schools were closed in Victoria as the government warned of an intensified fire risk.

Some residents have already chosen to leave their homes.