Police searching for missing Slough teenager are releasing a CCTV image of him at Slough railway station.
Syedtallah was last seen at 8.25am last Thursday (18 May) leaving his school in the town.
It is believed he may have travelled to London using public transport.
Syedtallah is around 5ft 5ins tall with black hair and was last seen wearing his school uniform of black jump, black trousers and a blue tie.
He had a change of clothes with him, which was a black hooded top and black trousers or jeans.
He also wears glasses.
Detective Constable Laura Bevan, based at Slough police station, said: “We’re naturally becoming very concerned for Syedtallah’s welfare, whose disappearance is totally out of character for him.
“We have reason to believe he may have travelled to London, and I am appealing to anybody who knows of his whereabouts to please report this via our dedicated missing persons portal, quoting reference 43230218016.
“If you see him, please call us on 999.
“I would again appeal directly to Syedtallah.
“If you see this message, you’re not in any trouble at all, but your family, and we, are very concerned for your welfare.
“Please get in touch with us to let us know where you are.”