Two more teenagers have been arrested over the death of a man found on the ground near Whitley Bay Metro station.
Lee Devlin, 40, from Whitley Bay, died in hospital after being found unconscious near the station at about 23:00 BST on Friday.
Two men, aged 18 and 19, arrested in connection with the incident have been bailed pending further inquiries.
A 16-year-old boy has now been arrested on suspicion of murder and a girl, 16, for causing grievous bodily harm.
Northumbria Police said both were helping with officers' enquiries.
Mr Devlin travelled by metro from Howdon and arrived at Whitley Bay station at 21:45 BST.
Northumbria Police said it was trying to establish what happened after his arrival at the station.
A post-mortem was inconclusive, officers said.