Two people have been hospitalised and treated for smoke inhalation after a bus caught on fire on the Sydney Harbour Bridge during peak hour on Thursday night.
Emergency services arrived at the scene near Milson's Point just after 5pm on Thursday and Fire and Rescue NSW confirmed 30 people were evacuated from the bus.
The incident caused traffic chaos during peak hour and authorities advised motorists to stay away from the Sydney Harbour Bridge.
Sydneysiders were advised to travel through the Sydney Harbour Tunnel or the Anzac Bridge and all lanes on The Sydney Harbour Bridge were temporarily closed
After 6pm on Thursday some lanes were opened to help the backlog of cars get through.
NSW Emergency Services minister David Elliot was one of the commuters stuck in traffic on the bridge and phoned radio station 2GB to inform listeners to stay away from the bridge.
On Thursday night NSW Transport minister Andrew Constance said an investigation would immediately be launched into the fire.
"I want to recognise the bus driver, who upon discovering the fire took immediate action and had it in the utmost of his mind the safety of those passengers on the bus to Northbridge," Mr Constance said.
"I also send my best wishes and hopes for those who have been taken to hospital this evening as a result of this fire."
The investigation into the cause of the fire will be led by the Office of Transport Safety.