British Transport Police are appealing for information after a bottle of hydrochloric acid was found on a Northern Rail train at Middlesbrough station shortly after 7 o'clock on Sunday evening.
The station was evacuated for a time and buses replaced train services.
4 fire appliances attended the incident along with 3 special appliances and 3 officers.It is believed the acid was in a soft drink bottle and caused the smell of burning when some of the liquid leaked from the container.
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The move is likely to lead to the loss of more than 1,500 jobs.