The Fire Service is investigating two suspicious fires in central Christchurch overnight.
Fire Service southern communications centre shift manager Andrew Norris said the first call came about 9.20pm to the McKenzie and Willis building on the corner of High St and Tuam St, which has been vacant since last year's earthquake.
It was burning fiercely when firefighters arrived.
Seven appliances attended and two crews remained at the scene this morning dampening down hotspots. The building was partially demolished by the fire.
"It's being treated as suspicious at this stage and a fire safety officer is investigating," Mr Norris said.
At 10.10pm emergency service were called to another fire at a vacant warehouse on Moorehouse Ave, less than 2km away.
It was also being treated as suspicious.