Hobson St in Auckland's CBD is closed to motorists as firefighters attend a fire at an apartment complex. 

There are reports of smoke in the building at the Altitude Apartments. 

A large crowd has gathered at the cordon area. 

Police are asking motorists to avoid the area. 

"Delays are expected in the area and diversions will be put in place while emergency services carry out their work," police said. 

Crowds have gathered at the cordon. Photo / Michael Craig 

Hobson St partially reopened just before 9.30am but one lane remains blocked for emergency services. 

Auckland Transport said due to a fire incident some bus services on downtown Auckland routes would be affected this morning.