A BLACK-CLAD robber threatened a teenager with a knife in Huddersfield Bus Station toilets.
Police have made an appeal for information about the terrifying ordeal.
The 13-year-old from Halifax had travelled to visit a friend.
While in the toilets he was grabbed from behind, spun round and held by the neck.
His attacker forced him into a cubicle and produced a knife before rifling through his victim's pockets and escaping with a small amount of cash.
The attacker was described as Afro-Caribbean, aged about 15 or 16 and 5ft 8ins tall of slim build.
He was dressed all in black which included a Nike baseball cap and trainers.
Detectives suspect a white male standing nearby could have been a look-out. He was 6ft tall with ginger hair and wore a baseball cap with Burberry checks.
Police are now studying CCTV footage of the station.
Anyone with information about the incident, which happened at about 5.30pm on Saturday, should contact Det Sgt Dave Campbell on 01484 436685.