Sydney Bomb Squad 'Defusing Device on Teenager'

Bomb squad officers were Wednesday working to defuse a "suspicious device" at a Sydney house that media reports said was strapped to a terrified teenager.

Police were alerted by an 18-year-old woman in the exclusive suburb of Mosman and were in the house with fire crews and paramedics on standby.

"Bomb squad officers remain inside the house where they are examining the device and supporting the woman," New South Wales police said in a statement.

"The process demands a high-level of skill and must be meticulous."

The Sydney Morning Herald said a balaclava-clad man had entered the house in the afternoon and placed the device on the girl, although police would not confirm reports it was strapped to her.

Other reports said a ransom note was attached to her neck.