US park rangers have launched an urgent search for more than 20 people unaccounted for following a flash flood in Arizona's Grand Canyon National Park.

"The National Park Service is asking the public to provide information for more than 20 individuals who may be missing or unaccounted for," the agency said on Sunday.

The flood struck the Bright Angel Canyon and Phantom Ranch areas, located in the remote interior of the park along the Colorado River, during Saturday afternoon.

The service urged anyone with knowledge of hikers who held campground reservations or who were travelling through the Bright Angel Creek corridor to contact authorities immediately.

Staff from the Grand Canyon National Park in the southwestern US are coordinating with the Arizona Department of Public Safety to conduct evacuations and locate potential victims.

As of Sunday, 62 individuals had been successfully evacuated from Phantom Ranch and the lower North Kaibab Trail, with authorities confirming no reported injuries so far.

Infrastructure damage

The surge of water caused catastrophic damage to the park's trail infrastructure.

Nearly all footbridges spanning Bright Angel Creek, a major tributary of the Colorado River, were destroyed, effectively eliminating hiker access across the waterway.

Consequently, the park service closed Phantom Ranch, Bright Angel Campground, and the entire North Kaibab Trail until further notice.

The Black Bridge and Silver Bridge, which cross the Colorado River, have also been closed indefinitely.

The Colorado River remains closed to all river traffic due to metal structures and heavy debris swept into the water.

The agency warned that additional thunderstorms and heavy rainfall are possible through Monday, potentially triggering further debris flows and rockfalls.