Three sisters and their nine children feared to have fled Britain to join Islamic State have crossed into Syria, a people smuggler claims. The disappearance of Khadija, Sugra and Zohra Dawood, from Bradford in West Yorkshire, and their children, aged between three and 15, sparked a missing persons alert by police when the group failed to return to the UK after travelling to Saudi Arabia.It has now been claimed the family were smuggled cross the border from Turkey into northern Syria, currently held by ISIS militants. The group of 12 were divided into two and the first group was taken across the border on Wednesday, a people trafficker told the BBC.The smuggler, identified as being in charge of some of ISIS&#039;s border operations, said the second group followed on Thursday.The parents of the women have said they do not support their actions and pleaded with others not to make a similar journey. In a statement, Dawood family members said: &quot;We do not support the actions of the sisters leaving their husbands and families in the UK and of taking their children into a war zone where life is not safe to join any group.&quot;We plea (sic) to anyone thinking about making a similar journey not to go.&quot;The husbands of two of the women broke down as they told of their anguish over their disappearance.Akhtar Iqbal and Mohammed Shoaib said they &quot;could not live&quot; without their families and begged them to come home. Earlier this week, police disclosed that one of the sisters had made contact and there was an &#039;indication&#039; they may have already crossed into Syria.The Dawood sisters travelled to Medina with their nine children on May 28 to go on a religious pilgrimage. They were due to return to the UK on June 11, but broke off all contact with their family in Britain two days earlier on June 9. A number of UK newspapers have reported that their brother fighting for ISIS in Syria and he persuaded his sisters over Skype to join him.