Fire crews are tackling a forest fire outside Blenheim.

Four appliances, including two water tankers, are at the scene of the fire about 10 minutes off of Dillons Point Road.

A Fire and Emergency New Zealand spokesperson said the fire was about 50m by 50m in area.

"We received a call at 12.32 and four units have responded.”

Blenheim Voluntary Rural Fire Force were at the scene and working to extinguish the blaze.

Smoke plumes could be seen several kilometres away from the site.