Canterbury fire crews remain on site of a vegetation fire near the town of Sheffield

At it's peak yesterday, 50 firefighters and three helicopters were battling the 60 hectare blaze at the Waimakariri riverbank, near the Gorge Bridge.

It's now contained and is being treated as suspicious.

Police are also investigating several vegetation fires in the Darfield and Rolleston areas early yesterday morning.

Fire and Emergency says they were called out to 11 fires - they're also being treated as suspicious.