Residents in part of Burnside have been told to evacuate immediately after an emergency alert warned of a high risk explosive substance in the area.

An emergency mobile alert issued at 3:34pm on Thursday warned people near Sheffield Crescent in Burnside to leave the area while police respond.

The alert said, “All members of the public are advised to immediately evacuate the area in the vicinity of Sheffield Cres Burnside Christchurch and surrounding area due to high risk explosive substance located.”

Fire and Emergency crews were called to the scene, but police were leading the response.

New Zealand Defence Force personnel have also been deployed to the scene.

The message added, “Police cordons are in place and will be removed once area safe.”

Senior Sergeant Craig Ellison told chrislynchmedia.com police were alerted to a concerning substance about 2.20pm today.

“People are asked to avoid the area. An increased police presence can be expected as safe removal of the substance is arranged.

Cordons will be removed once the area is safe.”

Residents nearby have been urged to follow instructions from emergency services and avoid the area while the incident is being managed.