Los Angeles, Jul 24 (IANS): A hydrothermal explosion occurred at a thermal area in Yellowstone National Park, one of the most visited national parks in the United States, damaging a boardwalk and forcing the closure of the area.

No injuries were reported and the extent of damage is unknown at this time, said the park service in a news release, adding that park staff and staff from the United States Geological Survey (USGS) will monitor conditions and reopen the area once deemed safe, Xinhua news agency reported.

The explosion occurred about 10:19 a.m. local time near Sapphire Pool in Biscuit Basin, located just north of Old Faithful, a cone geyser famous for its predictable eruptions, according to the National Park Service.

Park officials said that Biscuit Basin, including the parking lot and boardwalks, are temporarily closed for safety reasons.

"No other monitoring data show changes in the Yellowstone region. Today's explosion does not reflect a change in the volcanic system, which remains at normal background levels of activity," said the park service in the news release.

USGS also confirmed in a news release that "numerous videos of the event were recorded by visitors" and the boardwalk was damaged.

Videos shared on social media platforms captured the hydrothermal explosion that sent visitors running away as boiling water and debris raining down over the area.

"Hydrothermal explosions occur when water suddenly flashes to steam underground, and they are relatively common in Yellowstone," the agency said.

An explosion similar to that of Tuesday also occurred in Biscuit Basin on May 17, 2009, according to the agency.