Officials in the western U.S. state of Colorado say rescue operations for areas affected by deadly floods face new challenges because some people refuse to leave their homes as more rain heads to the mountainous region.
Authorities urged stranded residents to evacuate canyon communities such as Jamestown, where streets became raging rivers after the state received months' worth of rain in just a few days.
At least four people have been killed since the rains began Wednesday. A fifth person is missing and presumed dead. The death toll was expected to rise.
Forecasters said up to five centimeters more rain could drench the flood-hit areas on Sunday.
Rescuers said about 500 people were unaccounted for in Boulder and Larimer counties. They said some may have been unable to communicate with relatives after escaping the floods, while others may be awaiting evacuation without access to phones.
Helicopters have plucked hundreds of people from inundated homes. One helicopter carrying Colorado Governor John Hickenlooper on a tour of the region made two stops to pick up residents waving to be rescued on Saturday.
President Barack Obama has declared a major disaster in Colorado and ordered federal aid to supplement state and local recovery efforts.