Police are urging the public to come forward if they have information about missing Rothwell teenager Thorhijar Marchant.
The 15-year-old, of Rushton Road, was last seen at about 5pm on Tuesday, September 25, and was reported missing by his mother on Friday morning.
A police spokesman said: “We would urge him to give us a ring and let us, or his mother, know that he is safe and well.”
Thorhijar is described as having a pale to slight tanned, freckled complexion, a slight athletic build, mousey short hair and dark hazel eyes.
He is thought to be 5ft 7in, about 9.5st, and has a piercing in his left eyebrow.
He was last seen wearing a black/grey Adidas jacket, jeans and dark blue Timberlands.
The police spokesman added: “If anybody has any information or knows his whereabouts please could you give us a call on 101.”