ISLAMABAD — An Italian diplomat and two mountaineering workers in Pakistan said on Monday that an avalanche had stranded a group of four Italian and three Pakistani climbers on a mountain in the country's north.

A tour operator, Ashraf Aman, who arranged the expedition, said the avalanche hit the seven mountaineers when they were descending.

"I cannot comment on their condition at this stage, but a helicopter is being arranged. Volunteers from the area are being dispatched there," he said, offering no further details.

The four Italian climbers involved are Tarcisio Bellò, who led the expedition, Luca Morellato, David Bergamin and Tino Toldo. According to the Russian website Mountain.ru, which has been following the expedition, the four Italians have been injured.

Ambassador Stefano Pontecorvo confirmed Monday's incident happened in the northern district of Ghizar, but he also gave no further details.

According to Karrar Haidri, secretary of the Pakistan Alpine Club, authorities were trying to send a helicopter to Ghizar on Tuesday in an effort to rescue all the stranded climbers and bring them safely back to the base camp.

He said it was difficult to say what the condition of the climbers was.

"A rescue mission will begin tomorrow (Tuesday) and we are praying for the safety of stranded mountaineers," he told The Associated Press.

Mountaineers from across the world travel to Pakistan every year to try scaling its high northern mountain ranges. Harsh weather and conditions often prove a test for the most experienced of climbers.

Earlier this year, two European climbers — an Italian Daniele Nardi and Briton Tom Ballard — were killed on the Pakistani mountain Nanga Parbat, which is the world's ninth-tallest with a peak of 8,126 meters (26,660 feet), during bad winter weather.

Nardi, from near Rome, had attempted to scale Nanga Parbat in winter several times. Ballard's disappearance hit his homeland particularly hard as he is the son of Alison Hargreaves, the first woman to scale Mount Everest alone.

She died at age 33 descending the summit of K2.