There has been an explosion inside an apartment block in Sydney's inner-west with nearby residents evacuated and the police bomb squad called in.
Residents said they heard a loud explosion just after 5:30pm from inside a unit on Wentworth Park Road at Glebe.
Power in the street went out immediately after.
NSW Fire and Rescue responding to the fire then made a discovery which prompted them to call police.
Police then dispatched the bomb squad.
A police spokeswoman would only say that a "police operation" was underway and that traffic was being diverted from the area.
Residents say the same apartment complex was targeted in a suspicious blaze that damaged several units a month ago.
On May 17, a fire was started in the housing complex's courtyard and the blaze destroyed the bedroom of one unit and caused damage to several adjoining rooms.
Police at the time said they believed the fire was suspicious.
Wednesday night's incident has again forced the evacuation of residents and lead to the light rail being stopped for a short period of time during the evening peak.