Wellingtion: A New Zealand volcano used as a backdrop to "The Lord of the Rings" films erupted on Wednesday, sending a column of ash two kilometres (1.2 miles) above the North Island, scientists and witnesses said.
The official GNS Science monitoring service issued a potential threat alert after the 1:25 pm (0025 GMT) eruption at Mount Tongariro, which became active in August this year after lying dormant for more than a century.
While a nearby highway was closed as a precaution, Civil Defence authorities described the eruption as minor and told local residents they could expect light ashfall, advising them to stay indoors with windows and doors sealed.
Police said about 50 people were hiking around Tongariro when the eruption occurred but they were not in danger and there were no injuries.
Local resident Clint Green said ash was sent spewing about two kilometres into the air.
"It was pretty spectacular. All of a sudden a towering black plume just began erupting very quickly, skyrocketing up," he told Radio New Zealand.
"At first I didn't believe what I was seeing."
The August eruption, the first since 1897, hit domestic flights and closed highways. Air New Zealand warned the latest activity could also disrupt services and said it was closely monitoring the situation.
The mountain, in the centre of the North Island, is in the Tongariro National Park, which was used to depict the desolate wasteland of Mordor in Peter Jackson's hugely successful "The Lord of the Rings" movies.
Scientists warned about increased volcanic activity in the area this week, saying that neighbouring Mount Ruapehu was in danger of erupting as pressure built in a subterranean vent.
Resident Robyn Bennett, who lives about a kilometre from Mount Tongariro, said the volcano "just blew her stack" in the latest eruption and sent a huge black cloud over her house, giving off a strong smell of sulphur.
"It's hard to breathe if you go outside, it's pushing out quite heavily," she told Fairfax Media.
A volcanic eruption in the national park in 1953 caused New Zealand's worst rail disaster, creating a massive mudslide that washed away a bridge at Tangiwai, resulting in a passenger train crashing and killing 151 people.
New Zealand lies on the Pacific's so-called "Ring of Fire" and is a hotspot for volcanic and seismic activity.