HURRICANE Matthew was blamed for at least four deaths as it hit the US, flattening trees, knocking out power and triggering extensive flooding.

But the storm – which had triggered evacuation orders covering at least two million people – was downgraded to a Category 1 hurricane as it marched along the Atlantic coast, with maximum winds of 75mph.

The deaths, all in Florida, included an elderly couple who died from carbon monoxide fumes while running a generator in their garage and two women who were killed when trees fell on a home and a camper van.

The storm raked the city of St Augustine, Florida, and police blocked all access to the city early on Saturday as power crews repaired lines and downed trees were cut up.

Matthew also brought some of the highest tides on record along the South Carolina coast. Streets in Charleston were flooded, with reports of water as deep as people’s necks in some places.