A trespass incident between Cardiff Central and Cardiff Queen Street means that some lines are blocked.
As a result, trains running between these stations may be cancelled or delayed by up to 30 minutes.
Disruption is expected until 20:15.
Check before you travel:
You can check your journey using the National Rail Enquiries real-time Journey Planner.
Compensation:
You may be entitled to compensation if you experience a delay in completing your journey today. Please keep your train ticket and make a note of your journey, as both will be required to support any claim.