A 16-year-old boy has died after being stabbed at Seaford train station in East Sussex.
British Transport Police (BTP) said officers were called to the station following reports of a stabbing.
Emergency services, including Sussex Police and paramedics, attended the scene where the teenager was found with serious injuries consistent with being stabbed.
Despite efforts by passers-by and medics to save him, he was pronounced dead at the scene.
Another teenage boy has been arrested on suspicion of murder and remains in custody.
Witnesses described distressing scenes, with groups of shocked and upset people gathering near the police cordon as officers launched a murder investigation.
Detective Chief Inspector Paul Stanley, who is leading the inquiry, described the incident as shocking. He said: “This is a shocking incident which has resulted in the tragic loss of a young man this evening. The investigation remains in the early stages and the station will remain closed while we continue our enquiries in the area. I would urge anyone who may have witnessed what happened, or the lead up to it, to get in touch as you may have vital information which could help our investigation.”
The boy’s family has been informed.
Police have appealed to members of the public who may have information to contact them.
Witnesses can text BTP on 61016, call 0800 40 50 40 quoting reference 428 of September 10, or contact Crimestoppers anonymously on 0800 555 111.