A person has been hit by a bus in Auckland's CBD.

The crash happened at the intersection of Hobson St and Wellesley St West, where three police cars and cones are marking a crash site.

Due to a crash 3 lanes are blocked on Hobson St (Auckland CBD) after the intersection with Wellesley St West. Expect delays and take alternative route if possible. Use Port Link if heading to Motorways. ^LC pic.twitter.com/XHvQGMGjUr

— Auckland Transport (@AklTransport) December 5, 2017

St John Ambulance said one person was taken to Auckland City Hospital with serious injuries.

An AT Metro bus with a damaged windscreen is also at the scene.

Officer in charge Mark Hamilton said it was still unclear exactly how the 26-year-old man got hit by the bus but police believed he had been crossing the road.

He was hit about 9.10am and remained in a serious but stable condition at 10.30am.

"We are still trying to work out the sequence of events," Hamilton said.

Traffic had been "solid and steady" at the time.

Police have spoken to a number of people after the crash, including the bus driver who was "obviously upset" but otherwise okay, Hamilton said.

Who was at fault was not clear.

"We're still in the very early stages."

Today's crash happened in almost the same place and almost the same time as a pedestrian who was hit in June.

Father-of-four Daniel (Dann) Kopa, 34, later died in hospital.