An eruption on Whakaari/White Island is causing flight delays.

At least 10 flights have been cancelled and three delayed from both Tauranga and Rotorua Airports Thursday morning after an eruption at Whakaari.

GNS is currently investigating.

It said last week a new vent detected on Whakaari/White Island, which has been experiencing a minor eruption, was emitting an increase in volcanic ash.

Images show the column of ash emitting from Whakaari growing considerably in size in the two hours to 8am.

Air New Zealand says volcanic ash is across the flight path for both airports.

It says it will continue to monitor the ash cloud, and says any other customers on flights should keep an eye on the Air NZ app in case there are other routes affected.

The growing ash cloud as captured by GNZ cameras at Te Kaha at 8am on Thursday. Photo: GNS.

Air New Zealand's chief operational integrity and safety officer Captain David Morgan says the airline is continuing to monitor the movement of the ash.

"The safety of our people and our customers is our utmost priority."

More to come ...

-RNZ.