LATEST: SOCIAL media posts sparked an evacuation and police search of the Sydney Opera House and areas of beachside suburb Manly.

Hundreds of people were cleared and ferries after threats were made to the Manly ferry.

The public returned after the scare proved false.

"Following information on social media, police conducted an operation in the vicinity of the Opera House and Manly as a precautionary measure," police said.

3:45 PM: POLICE have now reopened the Sydney Opera House after earlier evacuating the Australian icon as part of a major operation.

Tourists were sent away from the landmark, although staff were allowed to remain inside, as officers searched for a suspicious object that was the subject of a threat received by police.

So far police are yet to release further details about the nature of the threat.

The threat caused the delay, re-routing or cancellation of some ferry services in the Sydney Harbour.

Parts of Manly were also involved in the police operation, which concluded earlier.

(All times are in Sydney local time)



3.20 PM AUTHORITIES have confirmed the Sydney Opera House has been cordoned off while officers search for a potentially suspicious object.

A New South Wales police spokesman has told Sydney media that the precautions were taken after authorities received a threat relating to an item inside the Opera House.

"It's a search for an object. There was a threat and we have to take it seriously," the spokesman told NewsCorp.

Police also shut down parts of Manly as part of another operation, but that has reportedly ended.

Reports suggest the Opera House search will likely be over soon.



Search at Sydney Opera House end still going but expected to be concluded soon. — Nick Ralston (@NickDRalston) January 14, 2016

Meanwhile an Opera House staff member has posted what appears to be an internal email to news-sharing site Reddit from the "Head of Security, Emergency Planning & Response".

All afternoon performances had been cancelled, and the public escorted from the site. Staff were allowed to stay put.

"Colleagues, A security threat has been received by NSW Police which they advise may involve the Opera House. Police are on site currently assessing the situation. The site has been closed to the public," the email read.

"This afternoon's performance of Stick Man has been cancelled and Tours, Creative Play and SATH have been cancelled until further notice.

"Members of the public have been asked to leave the site while Police assess the situation.

"NSW Police advise that SOH staff and contractors may remain in the building during this time. Staff are asked to keep their passes with them at all times.

"Any staff who would prefer to leave the site are free to do so in consultation with their managers.

"Pitt Street and Customs House should remain in their offices until more information becomes available.

The Incident Management Team are located in the Event Control area. We will continue to update as information comes to hand."

2:50 PM POLICE have confirmed there are two operations underway in the Sydney CBD and at Manly.

Police boats have been spotted patrolling the waters outside the Opera House.

They say the operation is ongoing and no further information is available at this stage.

2:30 PM (AEST) WORKERS and visitors at the Sydney Opera House have been evacuated as police clear people from the area.

Few details about the operation are known, but police are expected to make a statement.

UPDATE: The Opera House has been evacuated due to a police operation. #9News pic.twitter.com/g2ZGTL5YJU — Nine News Sydney (@9NewsSyd) January 14, 2016

The operation has disrupted regular ferry services to Circular Quay.

Australian comedian and The Last Leg talkshow host Adam Hills was due to perform two shows at the venue tonight.