KATHMANDU—An Indian climber and another from the Philippines became the first mountaineers to die on Mt. Everest in the current March-May climbing season of the world’s highest peak, hiking officials said on Friday.

Subrata Ghosh, 45, from India, died on Thursday below the Hillary Step while returning after reaching the 8,849-meter (29,032 feet) peak.

“He refused to descend from below the Hillary Step,” said Bodhraj Bhandari of Nepal’s Snowy Horizon Treks and Expedition organizing company. No other details were available.

The Hillary Step is located in the “death zone,” an area between South Col 8,000-meters (26,250 feet) and the summit, where the level of natural oxygen is inadequate for survival.

“Efforts are underway to bring his body down to the base camp. The cause of his death will be known only after post-mortem,” Bhandari said.

Philipp “PJ” Santiago II from the Philippines, died late on Wednesday at the South Col while he was on his way up, said Himal Gautam, a tourism department official.

Santiago, 45, was tired when he reached the fourth high camp and died while resting in his tent, Gautam added.

Santiago and Ghosh were both members of an international expedition organized by Bhandari.

Nepal has issued 459 permits to climb Mt. Everest during the current season that ends in May. Nearly 100 climbers and their guides have already reached the summit this week.

Mountain climbing, trekking and tourism are sources of income and employment for Nepal, one of the poorest countries in the world.

At least 345 people have died on Mt. Everest in more than 100 years since summiting expeditions were known to have started, according to the Himalayan data base and hiking officials.