A tropical storm has formed in the Atlantic and is expected to strengthen, prompting hurricane watches for some of the Caribbean islands devastated by Hurricane Irma.

More than 100,000 residents have been ordered to move away from a flood-swollen river in Pennsylvania as the remnants of Tropical Storm Lee dumped more rain across the US north east.

Flooding from the remnants of Tropical Storm Lee is being blamed for two deaths in Pennsylvania and numerous water rescues and road closures around a soggy north-eastern United States.