A teenager has died after being found unconscious in his cell at a Kent young offenders institute.

Alex Kelly, 15, had been identified as being at risk of suicide or self-harm at HMP Cookham Wood, near Rochester.

Staff attempted to resuscitate him before he was taken to hospital after being discovered in his cell at about 8.30pm on Tuesday.

But Alex was pronounced dead at 7.30pm on Wednesday, a Prison Service spokesman said.

He had been serving a 10-month detention and training order for burglary and theft from a vehicle.

A Prison Service spokesman said: "Every death in custody or the community is a tragedy for families and has a profound effect on staff and other offenders.

"The National Offender Management Service is committed to reducing the numbers of deaths in custody.

"Each death is subject to an investigation and, since 2004, these have been undertaken by the Prisons and Probation Ombudsman.

"Additionally for young people who die in custody there will be a Serious Case Review, commissioned by the Local Safeguarding Board. Strenuous efforts are made to learn from each death and improve our understanding and procedures for caring for prisoners, including young offenders.''

A Prisons and Probation Ombudsman spokesman said: "We are very sorry to be informed of the death of Alex Kelly and extend our sympathies to his family and friends, whom we will involve in our investigation if they wish, and try to answer any questions they may have.

"Our independent investigation will aim to identify the full circumstances of the death and whether there were any failings in Alex Kelly's care.

"Where possible we will identify lessons to be learned and make recommendations to the Prison Service to help prevent similar deaths in future. We also share any findings with the Coroner to assist with his enquiries."