SA man charged over torching couch

A man has been charged with arson and endangering life after allegedly setting fire to a couch in the Public Trustee office in Adelaide.

The 38-year-old man entered the office in Victoria square on Monday afternoon and poured petrol on a couch before setting it alight, police say.

He ran from the scene but was arrested nearby and is expected to appear in the Adelaide Magistrates Court on Tuesday.

A security guard quelled the fire and no one was hurt but the building was evacuated as a precaution.