An overnight grassfire has caused significant damage to Marino Conservation Park in Adelaide’s south.

In separate blazes, police believe a Kilburn house fire may have been deliberately lit and a grassfire is burning on Kangaroo Island

It started just before 11:00pm.

Trains running on the Seaford line were briefly halted after the fire jumped the train tracks.

Seventy-five firefighters brought it under control within an hour, protecting nearby houses.

The Metropolitan Fire Service said the western side of the 30-hectare conservation park was entirely blackened by the blaze, which has now been extinguished.

Separately, police said a house fire in Adelaide’s north this morning might have been deliberately lit.

It happened at Galway Street in Kilburn about 8:00am.

Emergency crews say the blaze was towards the front door of the home, which was unoccupied at the time.

The fire was quickly extinguished and investigations are underway.

The fire burning at Nepean Bay on Kangaroo Island. Photo: Country Fire Service

And a fire at Nepean Bay, about 5 kilometres north-west of American River on Kangaroo Island continues to burn into its second day.

The fire started in grassland north of Flea Castle Road at about 3:00pm on Friday and spread into heavy scrub.

A damaging wind warning is in place for large parts of South Australia this afternoon, including Adelaide, Port Lincoln, Mount Gambier, Maitland, Murray Bridge, Kingscote, Naracoorte, Meningie and Bordertown.

Wind gusts of up to 100 kilometres per hour are predicted, along with thunderstorms and showers, as a front moves across the state throughout the day.

-ABC