In the Western U.S. state of Colorado, farming communities are under mandatory evacuations.

They've been warned the already devastating floods that hit the region on Wednesday could surge as heavy rain continues over the weekend.

Authorities say the floodwaters, the worst to hit the state in decades, have claimed the lives of at least four, and possibly five, people.

Nearly 200 others in eastern Colorado remain unaccounted for, although authorities think some of them may still be stranded.

The National Weather Service warns of scattered showers and thunderstorms throughout the weekend.

That could trigger even more flash flooding - across stretches of the state already drenched and underwater.