There are delays of up to 40 minutes on First Great Western between London Paddington and Bristol Temple Meads, and between London Paddington and Cardiff Central due to signalling problems this morning (Sunday.)
This comes on top of planned diversions via Greenford, Banbury and Oxford due to works at Reading.
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Cold and frost this evening
Dry and cold today and much colder with frost overnight
It comes after an early morning evacuation of passengers from the departure lounge after a smoke alarm was set off.