A serial arsonist is thought to be targeting a family after cars were torched and a petrol bomb thrown at a house in Kurow, north-west of Oamaru.
The attacks have happened over the past week and Kurow constable Craig Bennett says they are linked.
The township's volunteer fire brigade has been called to four deliberately lit cars over the past week and all were seriously damaged.
The petrol bomb did not ignite.
Kurow constable Craig Bennett says the attacks are linked and the alleged arsonist is not thought to be a local person.
He says the people thought to be the targets of these attacks have been warned of the danger, but he is concerned that others may also get hurt.
The 500-resident community has been asked to be vigilant and report any unusual behaviour or any suspicious looking strangers in the town.