Multiple fire crews and three helicopters are fighting 12 suspicious fires in Canterbury, including a 50-hectare blaze near the small town of Sheffield.

Fire and Emergency were called to the blaze at the Waimakariri riverbank, near the Gorge Bridge, around 9pm last night.

Due to its location, it was too dangerous to fight the blaze last night, and crews returned to the scene this morning.

Crews also responded to 11 other small fires on roadsides and in gorse in the Selwyn District overnight.

These fires have been treated as suspicious.

Police told the Herald they were “making enquiries in relation to a small number of fires around Westland Place this morning. Emergency services were first notified at around 4.35am. Police are following lines of enquiry to locate the person or people involved”.