Drivers in Kent are warned to beware of thick fog which formed overnight.

The Met Office has issued a yellow weather alert saying areas in the north and west of the county are the worst affected.

A map warns drivers in Medway, Maidstone, Gravesend, Dartford, Sevenoaks, Malling and Tunbridge Wells should take particular care.

A spokesman said: "The warning area has been expanded, mainly to cover southeast England."

The alert, issued at 2am, warns of difficult driving conditions with rapid changes to visibility, slower journey times with delays to bus and train services possible and the chance of delays or cancellations to flights, especially at Gatwick.

The fog is expected to clear by 11am.

In the meantime, motorists are advised to avoid travel if possible, drive very slowly with dipped headlights, keep an eye on the speed, don't hang on the tail lights of the car in front and to use fog lights but remember to turn them off when the visibility improves.

Earlier in the week, the UK Health Security Agency issued a cold weather alert for central and southern England, which remains in place.