POLICE operations have completed at Sydney Opera House and Manly wharf with the areas earlier evacuated and some ferry services cancelled.

A New South Wales Police spokeswoman told news.com.au that police conducted the operations “in the vicinity of the Opera House and Manly ... after information was received on social media”.

“Police conducted the operation as a precautionary measure and that operation has now concluded,” the spokeswoman said.

She said no further information was available at this time.

Police earlier confirmed that two “police operations (were) underway” as people were evacuated from Sydney Opera House and at least one ferry service was cancelled and another was diverted and delayed.

A NSW Police spokesman confirmed police had received reports about an object inside the Opera House.

“It’s a search for an object. There was a threat and we have to take it seriously,” the spokesman said.

A Sydney Opera House employee posted about the police operation on a Reddit thread: “I’m inside the Opera House as an employee, there is no news for staff either just that a security threat was received and police operation is under way.”

A police op is currently underway in the #Sydney CBD & #Manly. As the operation is ongoing, no further info is available at this stage. — NSW Police (@nswpolice) January 14, 2016

Sydney Opera House and Manly Wharf were cordoned off during the operations.

The forecourt of the Opera House was cleared around 2pm on Thursday with police erecting metal barriers.

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

All tours of the Opera House have been cancelled for the day, an Opera House employee said.

The bars below the Opera House were closed and tourists were milling around Circular Quay during the operations.

There were also reports that surrounding Botanical Gardens area may have been evacuated near the Opera House.

All workers from the Opera house now outside away from the building #Sydney @abcnewsSydney pic.twitter.com/GOytxXBjqt — Scott Lilleyman (@scotty_rockstar) January 14, 2016

“The (operation) in Manly has been going on for a while,” the police spokeswoman told news.com.au.

A NSW Police spokesman confirmed the operation at Manly, on the northern beaches, was linked to the one at the Opera House, according to Nine News.

No people on steps of Sydney Opera house due to Police clearing area! pic.twitter.com/qoxRgeNcJE — Scott Lilleyman (@scotty_rockstar) January 14, 2016

Business Insider reported police had confirmed that they were conducting a “precautionary search” after one onlooker told of seeing police search a vessel.

One onlooker told Business Insider that at about 2.10pm police could be seen searching one of the service’s vessels.

A chef from Opera Bar told Business Insider: “Police just came in and said you have to evacuate, they didn’t give any reason why”.

Police were seen patrolling the exclusion zone with police boats and helicopters circling the area.

Some reports suggested the operations could have been the result of a hoax.

Police boat patrolling the front of the Opera House! I can see police walking through the buildingNeutral Bay Ferry pic.twitter.com/d5JfFgM1M2 — Scott Lilleyman (@scotty_rockstar) January 14, 2016

More to come.