Police operation: Sydney Opera House and surrounds evacuated.

A police operation unfolded at the Sydney Opera House this afternoon.

Members of the public, including Opera House workers, were evacuated from the site and surrounding areas.

Channel Nine News reports the 1:20pm ferry service from Manly to Circular Quay was cancelled and several others delayed. A search was also conducted around the Manly Wharf, but has now also concluded.

Fairfax Media are reporting the incident was sparked by a bomb threat on board a Manly Ferry.

Authorities have stated the searches were ‘precautionary’ and police did not uncover anything on site.

An Opera House employee informed AAP all remaining Opera House tours for the day have been cancelled.

Witnesses told Mamamia that while rangers were clearing the Botanic Gardens (approximately 25 patrons were present), a police helicopter hovered overhead. They ‘felt nervous’ and believed the epicentre to be Circular Quay, with the evacuation of the gardens as secondary.

A witness told Pedestrian TV, “They have roped it off, and all the people in the area had been moved on.”

NSW Police as stated, “As the operation is ongoing, no further info is available at this stage.”