(Reuters) - Matthew was downgraded to a Category 1 hurricane on Saturday by the U.S. National Hurricane Center.

Hurricane Matthew was about 20 miles (35 km) south-southeast of Charleston, South Carolina as it moved northeast 12 miles per hour (19 kph), the center said in an advisory.

Matthew had maximum sustaining winds of 85 miles per hour (140 kph), the center said.

(Reporting by Brendan O'Brien; editing by Mark heinrich)