KATMANDU, Nepal — Sherpa guides on Mount Everest are considering a boycott after the deadliest avalanche in the mountain’s history, a move that could disrupt the climbing season, a mountaineering official said.

Several Sherpas already have quit while others are still deciding whether to boycott following Friday’s avalanche, said Ang Tshering of the Nepal Mountaineering Association.

The disaster killed at least 13 Sherpas when a block of ice tore loose from the mountain and triggered an avalanche that ripped through teams of guides hauling gear. Three other Sherpas remain missing.

The Sherpas have expressed anger that there has not been a bigger response from Nepal’s government

“After losing so many of our brothers and friends it is just not possible for many of them to continue,” said Pasang Sherpa, who was not among those caught in the avalanche. “So many of us are scared, our family members are scared and asking us to return.”

Without the guides, it would be near impossible for the expedition teams to reach the 29,035-foot peak of Everest.