Adelaide Hills: Firefighters battling bushfire 'sparked by cigarette'

Firefighters are battling to contain a bushfire in the Adelaide Hills alleged to have been sparked by a cigarette butt.

The blaze started just after 11pm yesterday, with dozens of crews racing to land just off Montacute Road where homes were under threat.

Some residents were forced to flee as the fire raged out of control.

For the latest fire updates click here

“I thought I don't know how big it is I just saw orange and thought with the wind it could spread to almost anywhere,” local Sunny Chivaura told 9News.

“It started getting quite serious with some seriously big flames and yeah the family was really worked up,” fellow resident Derrick Lobban said.

Around five hectares of land has already been burnt, with the flames coming within metres of one home.

Authorities said while there are currently no visible signs of danger, the steep hills are making it a difficult fight.

“We can't access it with bulldozers and we can't bomb it with retardant, it's steep, it's full of fuel, it's difficult country to contain a fire in,” Peter Pew from the CFS said.

The cause is believed be a cigarette butt, with a woman fined by police..

With temperatures set to soar into the 40s in the coming days, the CFS has said it will remain on high alert.

“Until we can guarantee this thing is safe we're not going to declare it contained at all, we just can't afford for this to get out,” Mr Pew said.

READ MORE:Heatwave to bake Australia's states and territories

Paul Bierman from the Bureau of Meteorology said searing temperatures this week will lead to increased fire danger.

“We’ll be closely monitoring the conditions over the next few days and updated the forecast as necessary.”

Watch the full news bulletin on 9Now