A BLAZE that caused rush hour traffic chaos is being probed by police and fire chiefs.

Crews from three stations were called to the Old Print House on North Frederick Street shortly after 5.30pm last night.

The fire is believed to have begun in the roof space. The building is currently under renovation.

North Frederick Street was closed between George Street and Cathedral Street while John Street and Martha Street were also shut.

Crews were still on the scene three hours after the fire began.

A fire service spokesman described the city centre blaze as "challenging".