A group of 12 British women and children seem to have ignored emotional appeals from their families and crossed into territory controlled by the Islamic State (IS) group.

An IS smuggler told the BBC that the women and children had been split into two groups of six to facilitate the border crossing into Syria. The smuggler then called again and said that both groups had successfully made the journey.

Sisters Khadija, Sugra, and Zohra Dawood from Bradford, northern England, reportedly disappeared after taking part in a religious pilgrimage to Medina in Saudi Arabia with their nine children.

The sisters are all in their 30s, and the children are aged between three and 15. All 12 were due to return to the UK on June 11, but broke off all contact on June 9.

Sisters Khadija, Sugra, and Zohra Dawood.

A brother of the women is currently fighting with extremists in Syria, according to the BBC.

The husbands of two of the women — Akhtar Iqbal and Mohammed Shoaib — cried as they publicly appealed for their families to come home on Tuesday. "I miss you, I love you, all of you, I love you a lot. I can't live without you," Iqbal said, naming his wife Sugra and his five children.

"We were in a perfect relationship," Shoaib said. "Please come back. The kids, they cannot live without me. They miss me so much." He added: "I'm not angry, I'm fine, please come back, everything is normal. Come back to normal life please."

Watch the VICE News documentary, The Islamic State.

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One of the women made contact with her family in the UK earlier this week, according to British authorities.

A statement from the West Yorkshire Police released on Wednesday said that the North East Counter Terrorism Unit had received information about the communication, which also contained an "indication that they may have already crossed the border into Syria but this is uncorroborated."

On Thursday, the Dawood's parents and relatives released another statement, in which they said they were "devastated" by the sudden disappearance of their children and grandchildren.

"This has caused great distress to the family and has also stopped us from living a normal life in the UK since this incident," it read. "We are very worried about the children who could now be in a dangerous place."

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."