Trains through Swindon and Chippenham have been delayed due to an incident.
It’s understood police are responding to a report of trespassing on the railway – with the line closed in both directions.
The incident is believed to be in the Chippenham area. Further details are unclear at this early stage.
In a statement, a Network Rail spokesperson said: “A trespass incident on the railway between Swindon and Bath Spa / Westbury means all lines are currently closed.
“As a result, trains may be cancelled, delayed or revised.
“Disruption is expected until 18:15.”