Video: Yellowstone hydrothermal explosion sends tourists running at Biscuit Basin

A surprise hydrothermal explosion sent tourists panicking at Biscuit Basin in Yellowstone National Park on Tuesday, 23 July.

Dramatic footage showed a hot spring shooting steam, water, rock and dirt into the sky in front of a crowd.

The spectacle occurred in an area close to Sapphire Pool, which last saw an eruption in 1991.

Park officials said no injuries were reported and the extent of damage was unknown at the time of reporting.

The Biscuit Basin area was closed after falling debris damaged a boardwalk visitors use to avoid geothermal areas.