Police patrols in Christchurch are being increased near abandoned properties and in the city's red zone following a series of suspicious fires.
They are investigating three which occurred in the Mairehau, Linwood and Richmond areas overnight.
Detective Inspector Greg Murton says there have been a number of similar fires in the area over the past few months and police resources are being focused on these and arresting those responsible.
Mr Murton says there is a risk a fire may be lit in an abandoned property in which someone is squatting, who may become a victim of that deliberately lit blaze.
Reminder of fire ban
A blaze at Bottle Lake Forest in Canterbury has been contained on Thursday. A Fire Service spokesperson says crews were alerted just before 11am and it is also being treated as suspicious.
The Christchurch City Council says the fire is a reminder of the dry conditions and fire restrictions.
A total outdoor fire ban for Christchurch and Banks Peninsula, imposed in late December, remains in force. It says there are penalties for lighting fires during a ban and people can be made to cover firefighting costs.
