There are delays of up to 40 minutes on CrossCountry services between Birmingham New Street and Bath Spa and First Great Western Services between Cheltenham and Bath Spa.
It's all due to a signalling problem at Bristol Parkway. Disruption is expected to last until around 9am.
More top news
Becky Watts's family talk exclusively to ITV about their loss.
Becky Watts' uncle speaks exclusively to ITV News following the arrest of two people on suspicion of her alleged kidnap and murder.
The killer serving life for the murder of Jo Yeates has been sentenced to a further 10 months after admitting possessing child abuse images.