Chiltern Railway services from London Marylebone to the north are facing delays due to a fire on a train between High Wycombe and Saunderton.
There are currently no trains between High Wycombe and Princes Risborough and all services on the Chiltern main line are affected and expected to be clear by 5pm.
The railway operator is running services between London Marylebone and High Wycombe and between Princes Risborough and Birmingham Snow Hill.
They will divert as many trains via their London Marylebone- Amersham - Aylesbury - Princes Risborough line. However, journey times will be much longer than normal and there may be short notice cancellations to services.
Tickets will be valid with Great Western Railway between London Paddington and Reading and with Cross Country Trains between Reading - Banbury - Leamington Spa, on Virgin Trains between London and Birmingham and London Underground on reasonable routes.
For more updates visit www.chilternrailways.co.uk