MANITOU SPRINGS, Colo. — A thunderstorm has sent rocks, mud, debris and running water rushing down part of US 24 in a canyon in Manitou Springs, leaving some vehicles covered or stuck in mud.

The rockslide closed a four-mile stretch of US 24 Wednesday afternoon. El Paso County sheriff’s officials said there was no immediate report of injuries.

The American Red Cross opened a shelter for people seeking higher ground.

The National Weather Service had issued flash flood warnings Wednesday afternoon for areas scarred by the Waldo Canyon Fire last year and the Black Forest Fire this year, since soil and vegetation that normally would absorb rainfall there has been burned away.