Emergency crews have managed to contain a gas leak which is causing disruption in Auckland's Central city.

It started leaking from a manhole at the intersection of Customs Street East and Gore Street.

The roads will remain closed while gas detection equipment is used to ensure buildings are safe to enter and the gas has dissipated from the street.

Earlier this evening, CBD workers and residents were sent a text alert warning them to close windows and doors and evacuate if necessary.

The scene in downtown Auckland. Photo / Raphael Franks

Auckland Transport has detoured buses that terminate at Britomart.

At least 17 buses are backed up on Gore, Fort and Commerce Sts.

“Wake me if we start moving,” said one bus driver, forced to wait behind the cordon.

Police are managing traffic while Fenz deals with the gas leak.

Commuters have been told to expect delays and follow the directions of emergency services or transport staff.