The parents of three runaway schoolgirls feared to have joined the Islamic State in Syria have labelled British police 'hopeless' as they launch their own bid to bring their children home. School friends Shamima Begum, 15, Kadiza Sultana, 16, and Amira Abase, 15, left east London for Turkey last month before crossing into an ISIS-controlled area of Syria. Speaking from Turkey as they try to trace their children independently, the girls' parents claim they begged police to take their computers to check for any clues which may lead them to their whereabouts, but that officers only did so 'after many requests'. Scroll down for video . Schoolgirls Kadiza Sultana, 16, Shamima Begum, 15, and  Amira Abase, 15, (pictured at Gatwick airport) fled to Turkey before crossing the border into Syria where they are believed to have become ISIS jihadi brides . The parents of the three runaway schoolgirls have labelled British police 'hopeless' as they launch their own bid to bring their children home . The Bethnal Green Academy pupils are feared to have reached the conflict zone to become so-called 'jihadi brides' with ISIS. Parents and siblings of the teenage girls have now hit out at a series of alleged failures by the Metropolitan Police. Tasnime Akunjee, the families' lawyer, who has travelled with them to Istanbul, said that all contact with the British authorities and the academy had been 'an attempt to block them from finding out more about the circumstances surrounding the girls' disappearance'. Amira's mother Fetia Hussen, told The Times the people of Turkey have been very helpful. She said: 'We begged the police to take computers to check if there is anything on there useful to help find our daughters. 'The police only took these things after we asked them many times. We do not trust the police will do anything with this.' Scotland Yard said it would not comment on a live investigation. It comes days after a mother fled to Syria with her two young children to join the terrorist group. Rehana Begum Islam abandoned her husband of 14 years, vanishing overnight with her eight-year-old son and three-year-old daughter. The 33-year-old travelled from Heathrow to Istanbul on February 14 and then took an internal flight to Gaziantep, a city on Turkey's border with Syria. She is believed to have been helped by Syrian Mohammed al-Rashed, who was arrested last week on suspicion of getting the three east London schoolgirls across the border. On the journey to find the missing girls, their families went first to the Istanbul coach station where the teenagers waited 18 hours in the biting February chill for their bus to the Syrian border. There they spoke to a man who unknowingly let the girls in. He told ITV News they were 'smiling as they arrived' and 'smiling as they left'. Emotional: The families went to the Istanbul coach station where the teenagers boarded their bus to Syria . Questions: The families hope to find clues that may help them find or even contact their daughters . Anguish: The families of three missing London schoolgirls have travelled to Turkey to retrace their steps . Renu Begum, sister of Shamima, told ITV News: 'This is our next step basically to get the message out to them that we've followed them all the way out here. We want them to know that we love them.' Halima Khanom, sister of Kadiza, said: 'I don't really recognise my sister, the video and the CCTV that we saw. Because this is just not her and we just want to understand her, you know, to find some answers and get some help.' Abase Hussein, father of Amira, said: 'I don't know how to explain. I can't describe my feelings. I feel like my girl is next to me when I find someone that's on their last journey who saw them. I feel like my daughter is next to me - that's the feelings I have.' The east London schoolgirls flew to Istanbul from Gatwick with Turkish Airlines and now believed to be in based in the Syrian town of Raqqa – the Islamic State's self-declared capital. Last week it emerged that Sharmeena Begum, 15, a close friend of the trio and a fellow pupil at Bethnal Green Academy, left Britain before them in December. There are suspicions the trio kept in touch with Sharmeena who passed on information about how to follow in her footsteps. Those closest to all four girls suspect they were groomed by Islamists using social networking sites and secretive internet messaging software. The families have criticised police and others for failing to stop them. But their plight has raised questions about why the families themselves did not spot their conversion to radical Islam. Scotland Yard chief Sir Bernard Hogan-Howe has said the three schoolgirls would not face prosecution if they returned home.
Shamima Begum, 15, Kadiza Sultana, 16, and Amira Abase, 15, in Syria . Left east London for Turkey then went into ISIS-controlled part of Syria . Feared to have gone to conflict zone to become 'jihadi brides' with ISIS . Families have retracted their steps to find clues or even contact with girls . They say they begged police to take their computers to look for clues . But officers only took the machines 'after being asked many times'