Mountaineering clients of Boston-based firm trapped on Everest

Six mountaineering clients from a Boston-based travel risk and crisis management firm are unaccounted for and eight are trapped near Mount Everest after an earthquake in Nepal triggered an avalanche.

The eight that are trapped are on the mountain in camps above where the avalanche started, said Ann Shannon, a spokeswoman for Global Rescue.

The company had about three dozen clients in or around Everest when the 7.8-magnitude earthquake hit Kathmandu, setting off an avalanche on the mountain, Shannon said.

The death toll from the earthquake and subsequent avalanches has climbed to more than 4,000, the Associated Press reported.

Global Rescue provides security information to help people avoid crises while traveling, as well as medical and rescue information to help them escape risky situations. According to its website, the company has also completed rescue, evacuation, medical, and security operations in many locations, ranging from war zones in the Middle East to jungles in Africa.