Two young children were taken from their 'jihadi' mother as they returned from the Middle East amid concern they were being brainwashed into Islamic extremism.
The youngsters were taken into police protection at Luton airport last week after traveling to the UK from Istanbul with their 25-year-old mother.
It is understood to be the first case in which authorities have seized children from their parents over fears they were being radicalized.
Meanwhile nurseries are being urged to screen toddlers who display fanatical views.
Home Office guidance has been issued to teachers to who are expected 'to have the training they need to identify children at risk of radicalization'.
On New Year's Eve, two children, believed to be under 10, were taken from their mother as she was arrested at Luton airport on suspicion of terrorism offenses.
The Haringey-based family, who are understood to have links to Birmingham, had travelled from Istanbul with the Turkish airline Atlasjet, which also operates a flight to Gaziantep - nicknamed ISIS International for its proximity to the Syrian border.
At first, West Midlands Police said they had been taken into the care of social services. Later, officers said the youngsters were subject to a police protection order.
The force would not confirm whether they had been returned to their mother, but revealed they were not in the care of social services this morning.
It comes as guidance issued to nursery teachers expected to identify signs of radicalisation in children were slammed as 'heavy handed'.
Home Office documents being considered as part of a counter terrorism bill state senior management and governors need to be able to challenge extremist views and eradicate intolerance among toddlers.
The advice was described as 'unworkable' by politicians today, while human rights activists said it would not help prevent the spread of terrorism.
'Are they supposed to report some toddler who comes in praising a preacher deemed to be extreme? I don't think so,' David Davis MP told the Telegraph.
Isabella Sanky, policy director at human rights body Liberty added: 'The Government should focus on projects to support vulnerable, young people.
'Instead they are playing straight into terrorists' hands by rushing through a Bill that undermines our democratic principles and turns us into a nation of suspects.'
A Home Office spokesman this morning told MailOnline: 'The new duty in the Counter-Terrorism and Security Bill, to have due regard to the need to prevent people from being drawn into terrorism will be seen in a similar way to their existing safeguarding responsibilities.
'We are not expecting teachers and nursery workers to carry out unnecessary intrusion into family life but we do expect them to take action when they observe behaviour of concern.
'For schools, including nurseries and other childcare providers, we would expect staff to have the training they need to identify children at risk of radicalisation and know where and how to refer them for further help if necessary.'