Durham station has been evacuated and rail services are suspended between Newcastle and Darlington until further notice.
Rail passengers are facing a day of chaos after a gas leak led to trains being cancelled.
The leak was reported at around 11am on Wednesday and resulted in train services being suspended between Newcastle and Darlington.
Durham station was evacuated as engineers made their way to the scene to assess the problem.
The incident was affecting Virgin Trains East Coast, CrossCountry and First Transpennine Express services but all train companies said they were accepting each others tickets on ‘reasonable routes’.
CrossCountry passengers were able to use Grand Central services on any reasonable route.
A spokesman from Network Rail said: “Durham station has been evacuated and no trains are running through the area following reports of a gas leak next to the station, believed to be in the station car park.
“First Transpennine services from the south are terminating at Darlington. Virgin Trains East Coast and CrossCountry are diverting where possible or terminating at York.
“Passengers are advised to check National Rail Enquiries for the latest information.”
The A691 at Framwellgate, in Durham, was closed as a result of the leak, and Durham Police were at the scene.
Delays were expected to continue until 7pm on Wednesday.
Emergency engineers from Northern Gas Networks (NGN) are working to repair the gas escape. They say “third party damage” was caused to a medium pressure gas main.
John Richardson, customer operations area manager at NGN, said: “The safety of members of public is our number one priority. Due to the close proximity of the railway line to the gas escape we have temporarily closed the East Coast Main Line through Durham while we work to reduce the gas pressure and control the gas escape.
“The A691 Framwellgate Peth is also closed while we carry out investigations and work to repair the pipe.
“We’d like to apologise to customers for the inconvenience caused and thank everyone for their patience.”
A number of passengers took to Twitter to comment on the disruption.
Larissa said: “Delayed en route back to Derby due to gas leak. Knew I should have stayed in Alnmouth.”
Pip Jolley added: “Currently stranded at Newcastle as there has been a major gas leak at Durham station. Just waiting for the next train to London but God only knows when I’ll get in.”