A fire which damaged two ambulances at the St John station in Cromwell this afternoon is being treated as suspicious, police say.
A police spokesperson said a Fire and Emergency New Zealand investigator was expected to attend the scene following the fire, which emergency services were alerted to 4.30pm.
St John Central Otago area operations manager David Baillie said two off-duty ambulances were "heavily damaged" by the fire.
"The main Cromwell ambulance was not present at the ambulance station and is still fully operational and available to serve the region."
The station itself had not sustained any damage, and no staff or patients were at the station at the time of the fire, so no injuries had been reported, he said.
The cause of the fire had yet to be determined, he said.
"We will continue to investigate the incident and work with Fire and Emergency New Zealand and New Zealand Police."