Two teenagers were robbed of their mobile phones while walking on the Spen Valley Greenway yesterday (Sunday).
The 16-year-old boy and 13-year-old girl were near the Ravenswharfe Hotel in Huddersfield Road at around 6pm when two men demanded their mobile phones.
The boy told police they threatened to stab him when he initially refused, and was shown what he believed was a knife.
The robbers took a Blackberry mobile phone and an iPhone from the teenagers before leaving.
Neither victim was hurt, but both were left shaken.
Det Insp Jim Griffiths, of Kirklees CID, said: “We believe a cyclist passed the incident as it was ongoing. We’d ask that person or anyone with information to contact us via 101.”
The first suspect is described as Asian, aged 17 to 18, 6ft 2in to 6ft 3in tall, and of medium build. He had short, flat black hair and spoke in a deep voice with a local accent. He wore a thick, black jacket and black tracksuit bottoms.
The second man was described as Asian, 5ft 7in and chubby.