Five foreign mountain climbers died while climbing in the Swiss Alps, local police said. It's the deadliest accident this climbing season in Swtizerland.

The five, who have not been identified, plunged several hundred meters to their deaths from the Lagginhorn peak.

They all died at the scene of the accident, police in the southern canton of Valais said. The cause has not yet been established.

The five were all roped together. According to Swiss newspaper Blick, a sixth person in the group had decided to stay behind and not climb the final part of the route toward the summit because he wasn't feeling well, and was the one who alerted the Swiss mountain rescue. Blick also said the dead were German.

Rope parties of five aren't recommended by mountain guides; a good rule of climbing safety is to avoid more than four people on the same rope. But the 4,010 meter (13,155 ft) Lagginhorn is a relatively easy climb, possibly the most easily reachable of the Alps' 4000-meter peaks, and it often attracts less-experienced climbers. 

Swiss climbing journalist Natascha Knecht told the Basler Zeitung newspaper she was thinking of climbing the Lagginhorn by a more difficult route at the time of the accident, around midday local time on Tuesday, but decided against when she saw the weather turn foggy on the mountain. The five might have died, she added, when one of them slipped, fell and dragged the entire party into the abyss. While technically easy, the most frequently used route up the Lagginhorn has sections where it is exposed, meaning nothing shields climbers from a deadly fall. 

Last year, 151 people were killed in climbing or hiking accidents in Switzerland, according to data cited by Blick.