Police are investigating a suspicious fire at a religious building in the Adelaide suburb of North Brighton, as well as at a unit in the city's north.

Key points: Police say a fire at an Adelaide Baha'i Centre was deliberately lit

Police say a fire at an Adelaide Baha'i Centre was deliberately lit A unit at Elizabeth East also suffered damage from a suspicious fire

A unit at Elizabeth East also suffered damage from a suspicious fire Shots were fired at a home in Andrews Farm

A house also burnt down in a fire started by a barbecue at Coromandel Valley.

Police say the fire at the Baha'i Centre on Brighton Road in North Brighton was deliberately lit in the early hours of Wednesday morning.

They say a passing motorist spotted the fire at the front of the building about 2:20am.

She pulled over and woke the resident sleeping at the rear of the premises before attempting to extinguish the fire with a garden hose.

Metropolitan Fire Service crews attended and extinguished the fire.

Damage worth $15,000 was contained to the front door and wall.

Senior Constable Mick Abbott said crime scene investigators attended and examined the scene and determined the fire was "deliberately lit and suspicious".

"We're just after anyone who may have been in that vicinity … just prior to 2:20 this morning on Brighton Road who saw any suspicious activity to call Crime Stoppers," he said.

Unit fire also deliberately lit

Police say a fire at an Elizabeth East unit overnight was also deliberately lit.

Police and fire crews were called to Fletcher Road, Elizabeth East, about 12:45am with reports of a fire at the rear of the property.

The occupants safely evacuated the home before emergency services arrived.

The fire damaged the external rear wall of the premises.

Firefighters battle a blaze at a house at Coromandel Valley. ( ABC News )

A separate fire at a house on Annette Way, Coromandel Valley on Tuesday night was caused by a barbecue being left on, Senior Constable Abbott said.

Nearly 40 firefighters battled the blaze which engulfed the two-storey property, causing $650,000 worth of damage.

Firefighters also contained a blaze at a wrecking yard on Main North Road at Salisbury East on Wednesday morning.

The fire was sparked in a shed about 8:30am.

Two people were initially reported as missing but were found to have evacuated.

The fire was contained to the shed and a small grassed area nearby.

Shooting at Andrews Farm home

Also overnight, police say someone kicked in the front door of a house at Andrews Farm in Adelaide's north last night before gunshots were fired at the home.

Police at the Andrews Farm home that was shot at. ( ABC News )

It happened just before midnight in Eton Drive.

Five shots were fired at the house, penetrating roller shutters and damaging windows and internal walls.

Two people inside the home at the time were not injured.

"Police don't believe it was a random incident," Senior Constable Abbott said.

"We're obviously investigating the cause but certainly a very worrying incident for those people involved."

Officers and gun-detection dogs searched the area but the suspects could not be found.