MIAMI, United States (AFP) — Hurricane Joaquin strengthened to a Category Four storm yesterday as it moved away from The Bahamas, where it destroyed homes, caused flooding and left hundreds without power.

“Joaquin is a strong Category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale,” the US National Hurricane Center said in a statement, adding that “a gradual weakening is still anticipated during the next couple of days.”

Saffir-Simpson is a five-point scale.

Emergencies were declared along swathes of the US East Coast and residents evacuated starting on Friday after a powerful rainstorm lashed several states.

Forecasters warned of potentially deadly and unprecedented rainfall in parts of the East Coast and the rain was not expected to let up until tomorrow, triggering possible flash flooding.

North Carolina, South Carolina, Virginia and New Jersey all had warnings in place and in at least two coastal communities, people were told to flee because of dangerous rising waters.

Multiple water rescues were made in the towns of Carolina Shores and Calabash, in North Carolina, and a shelter opened for those displaced, local media said.

In South Carolina, Governor Nikki Haley told drivers to stay off the roads and warned power outages were possible during the weekend.

“We are expecting historic levels of rainfall this weekend,” she said in a statement.

Bill Martin, a meteorologist with the National Weather Service in Greenville-Spartanburg, South Carolina, told The Weather Channel: “We’re certainly very concerned about this situation.”

He added: “We’re expecting very high to extreme levels of rainfall over the next 48 hours.”

The National Weather Service warned of heavy rain and flooding across parts of the Mid-Atlantic, with Georgia in the south and New England in the north all under threat.