Suspect fire at Melbourne commission flats

A flaming mattress has caused up to 40 people to be evacuated from an apartment building in Melbourne.

Thick black smoke was pouring from windows at the housing commission flats on Park St in South Melbourne before fire crews found the mattress on the 24th floor on Wednesday night, MFB said.

That floor and the one above were evacuated, with 25th floor occupants able to return after a few hours.

Residents on the 24th floor were rehoused due to fire damage and electricity issues.

The Wednesday night blaze has been deemed suspicious.

The precast concrete panel high-rise building was built in the late 1960s by the now-defunct Housing Commission and still operates as social housing.