Usher and Tameka Foster's divorce was finalised in 2009

The son of Usher's ex-wife Tameka Foster is in a serious condition in hospital after being injured in a jet ski accident on Saturday.

Kyle Glover, 11, was hit in the head by a jet ski as he and a friend sat in an inner tube being pulled by a boat on Lake Lanier, Atlanta.

'He's bad,' Tameka, 44, tells Radar Online.

Usher, 33, and Tameka had 2 children together - Usher Raymond V, 4, and Naviyd, 3 - before ending their 2-year marriage in 2009.

Despite the split, the singer has remained close to Kyle and reportedly chartered a private jet so that his ex could be flown straight to her son's bedside.

'Kyle, You are strong.. You'll be saved I know it. I love you my baby. I need all #Prayers for my son! thanks you everybody!' Tameka wrote on her Facebook page over the weekend.

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Anna Duff