A former senior female ISIS commador has made the claim that trio are are now undertaking a four-month training programme in Raqqa and warned they are likely to die in Iraq or Syria, Telegraph.co.uk reported citing Sky News.
Teenagers Shamima Begum, Kadiza Sultana and Amira Abase ran off to Syria in February to follow a friend to Syria.
They are likely to be used as suicide bombers.The warning came as a separate report said teenage Manchester twins Salma and Zahra Halane are at the centre of an online recruitment drive to encourage girls to join them with ISIS.
Reports claim that the 17-year-olds, who left the UK last July, are part of a grooming campaign in "warped feminism".
Shamima, 15, Kadiza, 16, and Amira, 15, are believed to have contacted their parents to say they are safe and were but have no plans to return home, according to reports.
But a 22-year-woman, known only as Um Asmah, has claimed the girls' future will be dictated by their terror masters.