The group, all in their late teens or early 20s, is believed to have entered Syria more than a week ago and had sent messages to their parents to say they were doing voluntary work to help Syrians.
The nine medics have been identified as Lena Maumoon Abdulqadir, the youngest at 19 from Northallerton, North Yorkshire, Nada Sami Kader, Rowan Kamal Zine El Abidine, Tasneem Suleyman Huseyin, Ismail Hamadoun, Tamer Ahmed Ebu Sebah, Mohamed Osama Badri Mohammed, Hisham Mohammed Fadlallah and Sami Ahmed Kadir, The Telegraph reported.
One of the fathers, who lives in Britain, is convinced his daughter and her fellow medics have now crossed from Turkey into Syria.
They kept their plans secret from relatives back in the UK, telling them only when they had reached the border, BBC reported.
They flew from the Sudanese capital to Istanbul on March 12, took a bus to the border the next day and crossed over soon after.
The parents claim they are not getting the help they need from British and Turkish authorities.
The nine British-Sudanese are believed to have been joined by two Sudanese medics, one who is American-Sudanese and one Canadian-Sudanese.
According to the ‘Observer’, the students’ parents believed they are working in a hospital in Tel Abyad and wanted to work with IS, but they were almost certain they did not plan to take up arms.
The medics are said to have been born and grown up in England and were sent to Sudan to study at a medical school and experience “a more Islamic culture”.
A UK Home Office source told the paper the medics would not automatically face prosecution under anti-terror laws if they returned to the UK so long as they could prove they had not been fighting.
Lat month, three London schoolgirls believed to be of Bangladeshi origin, feared to have travelled to Turkey to join the dreaded Islamic State terrorists in Syria.
However, it is believed 60 British women and girls, including 18 teenagers, are believed to have travelled to war-torn Syria to join Islamic State militants, the UK's top counter-terrorism police officer said earlier this month.
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