It is the second tragedy to claim four lives there in three weeks after four Latvian climbers plummeted to their deaths from near the summit of Mt Cook on December 10.

The nationalities of those killed in the avalanche were not immediately available.

"Three people died at the scene and one later at Mt Cook village," police said in a statement.

"It is unknown what triggered the avalanche at this stage but inquiries into the cause of the accident will be made."

The two injured climbers were airlifted to Christchurch Hospital for treatment.

Initial reports said the avalanche was on Mount Cook but police said it was on neighbouring Mount Tasman, one of 19 peaks more than 3,000 metres high in the Aoraki-Mt Cook National Park.

Mt Cook is New Zealand's highest peak at 3,754 metres (12,388 feet), and the region has been described as a playground for adrenaline junkies and attracts thousands of visitors from around the world each year.

There have been at least seven other rescue operations since the southern summer climbing season began.

Mountaineer Noel Pullan, an expert on conditions in the area, said about 250 climbers would be in the region at this time of year.

"It has been a very bad season so far," Arthur McBride of Alpine Guides said, adding it was unclear what caused the avalanche.

McBride said Mt Cook village was in shock at the tragedy.

Meteorologist spokesman Gerard Bellam said conditions in the area were near perfect for climbing.

"It was fine with a southwest breeze. It is not surprising there were people up there, as it was suitable weather to climb the mountain today."

Mt Cook, in New Zealand's Southern Alps, has claimed a heavy toll since it was first scaled 99 years with more than 200 people killed.

In the worst recorded tragedy, five climbers died on January 19, 1930 when they were caught in a blizzard.

TERRA.WIRE