Explosion reported at Hoover Dam in US

Police in Boulder City of Nevada said they were headed to the Hoover Dam after reports of an explosion on Tuesday morning.

Videos posted on social media showed what appeared to be a fire or explosion in a building near the base of the dam.

A huge plume of black smoke swirled above the building.

Calls to police at the dam and Bureau of Land Management officials for information were not immediately returned.

The Boulder City Fire Department said it was responding to the scene, but had no additional information.