There are delays of up to 30 minutes on:
Arriva Trains Wales services between Cardiff Central and Cheltenham Spa, on CrossCountry Services between Birmingham New Street and Bristol Temple Meads and First Great Western services between Worcester Shrub Hill and Bristol Temple Meads and between Worcester Shrub Hill and Swindon.
Fewer trains are able to run through the area because of vandalism at Cheltenham Spa and services are liable to alteration or cancellation.
There is no indication as to when normal service will be resumed.
More top news
Adam Beeney coerced his victim into going back to his home in Bedminster where he raped him. Beeney has been jailed for 6 years.
Patsy Jacobs from Wiltshire has waived her right to anonymity to talk about domestic abuse. She was beaten in January by Nat Dimond.
A woman was attacked by two men at her home in Liden, Wiltshire. Police want to hear from anyone who may recognise the E-Fit image