British police report at least two people are dead after a helicopter crashed into a roadway in south-central London, near a key rail station for incoming commuters.

Local news reports say the aircraft hit a crane before hurtling to the ground, igniting a fireball that sent plumes of smoke into the sky. The helicopter is believed to have crashed into two cars.

The crash happened near Vauxhall Station, one of the main junctions for rail traffic entering the city. It happened during the morning rush hour, virtually halting traffic.

Ambulances and police vehicles are on the scene. Visibility is poor, due to fog and smoke from the fire.

Police have said there is no evidence to suggest the crash was linked to terrorism.