Up to 18 climbers are missing, and some probably injured, high in the Andes after a likely avalanche or ice wall collapse.
Officials said rescue teams braving high winds would try to reach the climbers - mostly German, Israeli, Argentine and Venezuelan - at 5,800 metres above sea-level on Alpamayo mountain, 300 miles northeast of Lima.
"There was an accident on Alpamayo mountain. We don't know exactly what kind of accident occurred, whether it was an avalanche or whether ice collapsed," said the head of the mountain rescue service in the department of Ancash.
"We do not know if there have been any fatalities, but in an accident of this kind, there are always injuries," he added.
Rescue helicopters were unable to reach the site because of strong winds, and search teams were expected to take 20 hours to reach the missing climbers on foot.