Los Angeles: Parts of Grand Canyon National Park, a popular natural wonder in the western United States, remained closed due to two growing wildfires that have prompted the Park Service to evacuate hundreds of visitors, officials have said. 

"The North Rim of the park remains closed until further notice to support firefighting operations and ensure public safety for the Dragon Bravo fire and the nearby White Sage Fire," said park officials in a statement on Saturday.

"Smoke is expected to remain visible from the South Rim, and air quality conditions may vary depending on fire behaviour and wind patterns," they added.

The White Sage Fire, started Wednesday evening following a thunderstorm that moved through the area, has expanded to over 19,000 acres (76.9 square km) with zero per cent containment as of Saturday morning, according to InciWeb, an interagency all-risk incident web information management system provided by the United States Forest Service.

Large fire growth has been observed and can be expected to continue, said an update on the website.

Officials said Friday on Facebook that Grand Canyon staff safely evacuated approximately 500 guests from the North Rim due to the White Sage Fire, adding that "all visitors have left the area, and park employees and residents remain sheltering in place."

The nearby Dragon Bravo Fire began on July 4, but its fire behaviour and growth have increased in recent days due to hot, dry and windy conditions, reports Xinhua news agency, quoting InciWeb.

The fire has burned about 5,000 acres (20.2 square km) so far and remains zero per cent contained. (IANS)