Signal problem delays trains from Cardiff to Newport
A signalling problem caused disruption to trains between Cardiff Central and Newport.
At one stage services were delayed by up to 90 minutes, and shuttle buses were running between the two cities.
Services run by First Great Western, Arriva and Cross Country were affected for two hours, with a backlog of delays following.
Arriva Trains Wales said the signalling problem was at Rumney Bridge, but it was cleared at 15:45 GMT.
Connecting services to north Wales, the West Midlands, Manchester, Taunton, Portsmouth and London have also been affected.