http://www.bbc.co.uk/news/world-us-canada-18656648

The storms formed in the Midwest and then moved east to the mid-Atlantic states

Some two million people are without power after violent storms hit the region around the US capital, Washington DC.

The storms swept from the Midwest states to the region around Washington, packing winds of up to 80mph (130 km/h).

The power outages left many sweltering without air conditioning amid a record-breaking heatwave.

At least nine deaths have been linked to the storm, officials say.

The storm is locally referred to as a "derecho" - a violent, straight-lined windstorm associated with a fast-moving band of severe thunderstorms.

It left behind felled trees, streets littered with fallen branches and downed power lines.