Four Spanish climbers were missing in northern Pakistan, their tour operator said on Tuesday.

The missing mountaineers were part of an 11-member Spanish team attempting to climb the 8,068-metre Gasherbrum 1, said Syed Anwar from Lela Peak Expedition, which organised the tour.

Three lost contact with the rest of the group after pushing ahead and reaching the summit at the weekend. Another went missing on the way back to camp after turning back 100 metres from the summit with exhaustion.