Police investigate suspicious Sydney fire

Police are investigating a suspicious house fire in Sydney's southwest.

Emergency services arrived at the property on Coolibar Street in Canley Heights just before 7pm on Thursday (AEST).

No one was at home at the time, but the fire caused extensive damage, police said.

Officers are investigating the cause of the fire, which is being treated as suspicious.

Anyone with information about the incident has been asked to contact police.