There's disruption on First Great Western services between Bristol Temple Meads and London Paddington and between Cheltenham Spa and London Paddington due to a person being hit by a train between Swindon and Didcot Parkway.
Trains may be delayed by up to an hour, and buses have been requested to run between Swindon and Reading.
Tickets are being accepted on CrossCountry and Virgin Trains services.
More top news
Cloudy day, patchy drizzle
Cloudy day, improving tomorrow
Alex Sims, 10, has a rare auto immune disease and without a transplant he will die.