Updated: 2:21pm UK, Tuesday 07 August 2012
A volcano dormant for over 100 years has spewed an ash cloud across New Zealand, causing some disruption to flights.
Mount Tongariro, one of three volcanic peaks on North Island, exploded with bright flashes and thunderous booms, blanketing the area with a thick, grey carpet of volcanic ash.
Flights to and from provincial airports, including popular tourist spot Rotorua, were delayed or cancelled.
Local roads were closed for a time, but there were no reports of damage or injury.
The Ministry of Civil Defence and Emergency Management advised residents to stay indoors and to protect their eyes, mouth and nose if they were caught in the ash.
Experts said the spew of rocks and steam from the snow-capped, 1,978m-high peak was caused by a build-up of volcanic gases.
"We've had unusual seismicity, we've seen some volcanic gas signatures," said volcanologist Brad Scott.
"But, to be quite honest, we didn't see anything in the latest data up until last night that really indicate the volcano was ready to erupt."
Meteorologists said the ash cloud was being blown eastwards towards the Pacific Ocean.
Neighbouring Mount Ruapehu is the most active volcano in New Zealand, last erupting in 2007 when it sent a mud slide down the mountain.
New Zealand is on the Pacific Ring of Fire and has frequent seismic activity.
An earthquake last year in Christchurch on South Island killed 185 people and destroyed much of the city centre.