A cyclist has died after being hit by a bus outside Sydney's Taronga Zoo.

Emergency services were called to the popular attraction on Bradleys Head Road in Mosman about 10.30am.

The cyclist, a man in his 50's, died at the scene.

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The bus driver was not injured but was taken to hospital for mandatory testing, police said.

Four passengers on the bus who were uninjured.

The main entrance to zoo has been closed, with heavy traffic is reported in the area.

Traffic diversions are in place and motorists are urged to avoid the area.

Police are investigating and a report will be prepared for the Coroner.

Taronga Zoo said it remains open.

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