Train passengers faced mounting delays and disruption on the West Coast Mainline on Wednesday night after an incident closed part of the busy route.
Emergency services were called to a train between Warrington Bank Quay and Crewe, in Cheshire, causing all lines to be blocked, Virgin Trains said on Wednesday night, forcing services to halt.
The disruption was said earlier to have been been caused by safety checks on a train between the two stations, but operator Virgin later said emergency services were dealing with an incident.
“Investigations are ongoing so we’re not sure exactly what’s happened just yet,” the company told one customer on Twitter.
Trains continued to run between London Euston and Manchester Piccadilly.
British Transport Police has been contacted for comment.
National Rail said alternatives were being sought to transport passengers to and from Crewe and stations further north.
“Coaches have been requested to run between Liverpool South Parkway and Crewe,” its Twitter account wrote to one person.
Virgin serves around 100,000 passengers a day on its West Coast routes, with 57 services passing through Crewe on an average weekday.
This article has been updated.