Search underway after 4 climbers fall on tallest mountain in North America

A search and rescue mission is underway after four people fell while climbing Mount McKinley at 18,200 feet, according to the National Park Service.

Mount McKinley -- located in Alaska's Denali National Park and Preserve -- is the tallest peak in North America, according to the NPS.

The climbers, part of a seven-member climbing team, fell in the vicinity of Denali Pass, according to the NPS.

The NPS received a report of the incident at around midnight Thursday after two other climbers were evacuated by helicopter from the mountain at around 11 p.m. Wednesday, as part of a separate incident, the NPS said.

Three members of the climbing team returned to High Camp at 17,000 feet after attending to their fallen partners, the NPS said.

The NPS said it is actively responding to the incident. Weather conditions on the mountain are improving and will soon enable helicopter operations, the NPS said.

The extent of the climbers' injuries and their condition remains unknown, the NPS said.