As communities in the central US grapple with widespread devastation from a line of deadly storms that spawned dozens of tornadoes this week, forecasters are warning of another grave threat to the region: relentless rain into the weekend,

Deadly storms and flooding rains left a path of destruction across 14 states in the US South and Midwest, knocking out power to more than 400,000 customers.

More than 30 tornadoes have already swept across the region, and at least seven people were killed in three states. Much of Kentucky was under a flash flood warning.