Rail passengers have faced major travel disruption in south Wales because of a signalling fault on Saturday afternoon.
Most Arriva Trains Wales, CrossCounty and Great Western Railway services were cancelled or faced delays of up to 70 minutes following the failure between Newport and Cardiff Central.
Some lines later reopened with a limited number of trains running, but the disruption was due to last at least until the end of the day.
Some replacement buses were put on.
Arriva Trains Wales advised customers not to travel between Newport and Cardiff and to postpone their journeys.
Routes between Gloucester, Manchester Piccadilly, Holyhead and Pembroke Dock, Fishguard Harbour, Maesteg, Milford Haven, were also affected.
Great Western Railway services between London Paddington, Portsmouth Harbour, Taunton and Cardiff Central, Swansea, were also disrupted, along with CrossCountry services between Nottingham and Cardiff Central.
National Rail has advised customers to check their routes before they travel.