KATHMANDU — Nepal is adding more medical staff at Mount Everest's base camp and working to speed up rescue efforts, officials said on Tuesday, in steps to boost safety after 16 local guides were killed by an avalanche last year in the deadliest disaster ever on the world's highest peak. Four doctors, up from two or three in the past, will be stationed at the base camp's emergency room tent, which will be equipped to handle almost any medical need, said Devi Bahadur Koirala of the Himalayan Rescue Association Nepal. Authorities have also arranged for rescue helicopters to airlift sick or injured climbers from base camp within 90 minutes, Koirala said. Previously, each team would arrange their own rescue, which would often take hours. Sick or injured climbers would be first treated at the base camp and airlifted to their lower attitude clinic at Pheriche, located at an elevation of 4,370 meters (14,340 feet) and if necessary to the capital, Kathmandu. During the spring climbing season that runs from March 1 to May 31, more than 300 foreign climbers attempting to scale Everest and their local guides and support staff swell the base camp's population to more than 1,000 people, turning the area into a tent village. In addition, hundreds of trekkers hike up to the base camp during the same time. Koirala said most of their patients suffer from high altitude sickness, but other common problems include injuries and broken bones of people who slip and fall on the mountain slopes. In the 2014 avalanche that struck just above the base camp, several local guides and porters who were carrying equipment and supplies at the beginning of the season were swept away by snow, hit by falling ice and rocks, or fell into crevasses. Nepal was criticized for not having a rescue plan during disasters or any government presence at the base camp despite charging climbers huge permit fees. Nepal's government is also setting up a full-time office tent at the base camp this season which will have officials throughout the climbing season to provide security, settle disputes among climbers and monitor the activities of the hundreds of climbers and guides at the base camp. They would provide information on climbing conditions and weather on the mountain and have communication equipment to quickly respond to any problems. More than 4,000 climbers have scaled 8,850-meter (29,035-foot) Mount Everest since 1953, when it was first conquered by New Zealand climber Edmund Hillary and his Sherpa guide, Tenzing Norgay. Hundreds of others have died in the attempt. — AP