Flash flooding after heavy rain sweeps across London. [Source: BBC]

Heavy downpours and thunderstorms have caused severe flash flooding in parts of London.

There were reports of vehicles becoming stranded as water quickly rose to block dozens of roads and affected underground lines.

The fire brigade said it had taken about 300 calls – mostly about flooded basements or roads – in the space of a few hours on Sunday.

Officials have advised against travelling in hazardous conditions.

An amber thunderstorm warning is in place for much of southeast England, with 75 to 100mm (3in to 4in) of rainfall forecast in some areas.

The Environment Agency issued two flood warnings for areas in London near Beverley Brook in Worcester Park and West Barnes.