Christchurch police are investigating two suspicious fires at public bathrooms on Sunday and are working to establish whether they are linked.

A police spokesperson said officers were called to a suspicious fire at a Strowan Road business about 2pm.

“Enquiries are continuing,” the spokesperson said.

The fire happened inside a bathroom at the Z service station, causing extensive damage.

The service station remained closed late Sunday afternoon.

Earlier, Fire and Emergency crews were called to a fire at a toilet block at Northlink retail centre in Northcote.

Crews from Redwood, Ilam and Christchurch City stations responded to the bathroom fire at the retail centre on Langdons Road about 11.30am.

There were no immediate reports of injuries, but significant damage was reported.

Local resident Joe Napoleon said a whole block of shops, from Noel Leeming to Coffee Culture, had been evacuated.