Police, paramedics and the ambulance service have all raced to Kirkstall Road in Leeds following reports three people have been spotted on the railway bridge.
The road has been shut in both directions by police, with vehicles and buses being diverted away from the area as a result of the ongoing incident.
There has been massive disruption to travel, with train services which would normally use the line having to be cancelled or delayed.
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Northern Rail has warned disruption is expected between Horsforth and Leeds until at least 2pm. It has suspended all services at Headingley and Burley Park.
Buses are running in place of trains between Leeds and Harrogate.
Our traffic partner, Inrix, is reporting delays in the area. In its latest update, it said: "A65 Kirkstall Road closed in both directions.
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"Queuing traffic due to police incident between Viaduct Road (the Shell Garage) and the Cardigan Arms. Congestion to Burley Road and Canal Road as traffic diverts."
First Bus West Yorkshire is also diverting its 508 service via Kirkstall Hill, Burley Road and Willow Road.
LeedsLive has contacted West Yorkshire Police for a statement on the ongoing incident.
