A 27-year-old man from Middlesbrough has been arrested on suspicion of endangering railway safety after a bottle containing hydrochloric acid was left on a train.
Middlesbrough railway station was cleared and the Northern Rail service to Darlington evacuated after the corrosive liquid was found on Sunday evening, sparking a major response by the emergency services.
British Transport Police released two CCTV images of a man officers wanted to trace, and a man has since been arrested on suspicion of endangering safety on the railway.
"We would like to thank members of the public for coming forward with information, as well as the media for assisting with our appeal.
The man remains in custody and is currently helping police with their inquiries."
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Kerrie Gosney brings you Sunday night's forecast
Cold with wintry showers overnight and on Monday.
Cold air from Canada will turn showers wintry overnight into Monday morning. Snow could settle over higher routes. Icy patches possible