Eight of those injured were flown to hospitals and others who suffered non-critical injuries were taken by ground transportation, the Hualapai tribe’s emergency operations said in a statement.

A tour bus collided with a visitor’s personal vehicle near the Grand Canyon West parking lot, KTNV television news of Las Vegas reported, citing a spokesman for a tour company.

The accident occurred in Grand Canyon West on the Hualapai reservation, an area that includes the West Rim of the Grand Canyon and the Skywalk, an observation deck that protrudes into the canyon, some 1,200m above the canyon floor.

The land is distinct from the Grand Canyon National Park, which receives about 5 million visitors per year, according to the Grand Canyon’s visitor centre.

The cause of the accident was under investigation by the Hualapai Nation police department and the Arizona department of public safety, the statement said. Multiple tribal, state, and local fire and rescue agencies responded.