Two elite Japanese mountain climbers fell from Pakistan's K2, officials said Sunday, following an attempt at a helicopter rescue that spotted the motionless pair but was forced to turn back.

Veteran mountaineers Kazuya Hiraide and Kenro Nakajima were attempting an ascent of the jagged western face of the world's second highest mountain, using an expert climbing style prioritizing speed and relying on minimal fixed ropes.

But on Saturday "they fell from a height of 7,500 meters," Alpine Club of Pakistan (ACP) Secretary Karrar Haidri said in a statement.