Christchurch police are appealing for information following an increase of powerline tampering and theft across the city

Incidents have recently occurred in Addington, Phillipstown, West Melton, Halswell and Marshlands.

Police say tampering and the theft of copper has led to outages on affected streets, and powerlines have been left in a dangerous state.

Senior Sergeant Roy Appleby says offenders are putting themselves and others at extreme risk of electrocution, for a small return.

He urges anyone who hears or sees anything out of the ordinary to contact police.