Police are appealing for witnesses following a robbery in Rastrick, Brighouse on Tuesday, 11 April.
Three males, aged 16 and 17, were walking in the vicinity of Carr Green Park at around 7.30pm, when they were approached by two youths who brandished a flick knife and demanded the victims hand over cash.
One suspect is described as mixed race, 5ft 8in tall, of skinny build, around 16 to 18-years-old and with a short moustache. He was wearing black jogging bottoms, a dark coloured puffa jacket and dark coloured trainers. He spoke with a local accent and he is believed to have produced the flick knife, which he held in his left hand.
The second suspect is described as white, with a dark complexion, 6ft tall, and between 16 and 18-years-old. He was wearing grey jogging bottoms, a black coat and dark trainers.
Detective Sergeant Nick Speed, of Calderdale CID, said: "This was an extremely frightening incident for those involved and our enquiries remain on-going. I would appeal for anyone who witnessed the incident or anyone who has any information to get in touch with police. I would also urge anyone who saw two males acting suspiciously in the area or anyone has come across the items taken by the suspects, to also get in contact."
Information can be passed to Calderdale CID on 101.