Most lanes on the Sydney Harbour Bridge are closed after an accident between a semi-trailer and several cars.
At least one person is believed trapped by the accident which happened after midday.
"Emergency services are on site but there are extensive traffic delays in both directions," said a spokeswoman for the Transport Management Centre. All southbound buses that normally cross the bridge are now terminating at North Sydney Station.
Northbound buses are using the Sydney Harbour Tunnel.
"Passengers will be able to use their tickets to catch the train between North Sydney and Central instead," the spokeswoman said.
