Trains are being delayed in and out of Huddersfield after a person was hit on the line near Dewsbury.
Officials have not yet confirmed if the incident is a fatality.
A spokesman for Network Rail confirmed the person was struck by a train at 2pm close to Dewsbury station.
The line is still open but delays of up to an hour are expected for many services using the busy Transpennine route.
About a dozen police officers could be seen close to where the tracks cross over Huddersfield Road.
Disruption is expected to last until 6pm while British Transport Police and Network Rail officials investigate.
Travel updates can be found online at www.nationalrail.co.uk or on Twitter via #DewsburyTrains