The order came after a rock face 3,400 metres (11,220 feet) up the Matterhorn crumbled on Tuesday, forcing the evacuation of about 70 people.

Officials in nearby Zermatt and the local guides' association decided late on Tuesday to ban climbers ascending the 4,478-metre peak until further notice.

Work is now underway to make the rock face that crumbled in the soaring temperatures secure and should take at least three days, geologist Jean-Daniel Rouiller told Swiss news agency ATS.

No one was hurt in Tuesday's incident.

Helicopters evacuated about 70 mountain enthusiasts from the Matterhorn as a precaution.

The unusually hot weather -- which has seen temperatures consistently higher than 30 degrees Centigrade (86 degrees Farenheit) for weeks -- is melting the snow and ice at high altitude that normally binds the rock together.

But climbers and walkers were undeterred on Wednesday, with groups setting off into the neighbouring mountainous regions of Saas-Fee and the Val d'Anniviers, according to officials from Alpine refuges.

TERRA.WIRE