Toll of kids missing from school
More than 2,600 children as young as three have disappeared from Scottish schools for prolonged periods of time and some never found, according to new figures obtained by the BBC.
In some cases, children are marked as missing because they have moved house and failed to tell the school.
Agencies say others disappear for more "sinister" reasons including abuse and forced marriage.
In the past five years, 2,619 children aged three to 16 have gone missing.
The figures, obtained under the Freedom of Information Act, include 719 children going missing in the past year.
Children are categorised as "missing in education" if the authorities are unable to track them down from four weeks or more - or two to three days in the case of vulnerable children .
Some 24 children were never traced - in the main because authorities say they moved abroad.
Several of the councils said they do not record those who are "not returned" and do not know about or record cases of forced marriage.
Fife council said that in one case "the family moved to France" but it was "never verified".
Specialist agencies say in addition to the children recorded as missing from school, there are others who disappear without being monitored because families tell a plausible story to the school before. for example. forcing the child to marry abroad.
One specialist agency worker, who cannot be identified for safety reasons, said: "Children going missing is significant to begin with and should worry everyone.
"Children going missing but not being reported missing, now that is a real problem.
"Now, if the parents are not going to go forward to report a child missing either because they have been taken out of the country, or they have been subjected to all sorts of horrors like female genital mutilation, like forced marriage, they could have been abducted and sold as a bride...that is a real, real worry."
A system was created to record and report missing children after the murder of five-year-old Danielle Reid in Inverness in 2002. Her body was not found for three months, partly because her mother told the authorities she had moved to a school in Manchester.
Ministers announced the Children Missing in Education system in 2005 with a unique identifying number for each child to track pupils between schools and council areas.
The inquiry following Danielle's murder stated: "If we do not share in the early detection and support of Scotland's vulnerable children, then the consequences of their subsequent neglect and abuse will re-visit us for many generations to come."
The system means most missing children should be recorded but the figures also show that some children have not been traced for 10 months and others have never been located.
Earlier this year, the Jay report inquiry in Rotherham revealed "shocking levels" of abuse and highlighted links between children who go missing and sexual exploitation.
In the past five years, 1,385 children have been recorded as "missing in education" in Glasgow, compared to 267 in Fife, 164 in North Lanarkshire, four in South Lanarkshire and 22 in Edinburgh.
A Scottish government spokesman said: "These are concerning figures and we are currently looking at how we can tackle the issue of children missing from education.
"The Scottish government is committed to ensuring the safety and wellbeing of Scotland's children and young people, and education and school staff play a crucial role in the support and protection of children.
"The national Children Missing from Education Guidance emphasises that where there is any concern that a child may be at risk, child protection procedures should be followed.
"We support local partners on the ground to continually improve child protection measures, including protecting children from risk of harm and neglect. This ensures children get the help they need when they need it."
The spokesman added: "Forced marriage and child sexual exploitation are abhorrent crimes. We continue to work with local authorities, law enforcement agencies, children's charities and other third sector organisations, as well as Parliament, to tackle child sexual exploitation and we legislated in 2011 to protect those in or at risk of being forced into a marriage.
"From 30 September 2014, the Scottish government created an additional layer of protection by making it a criminal offence to force someone into marriage."
A spokesman for North Lanarkshire Council's Learning and Leisure Services, said: "We have robust procedures in place and, when a child or young person is registered as being missing, a thorough investigation is immediately carried out.
"The reasons for a child or young person being classified as missing include returning to their original country, moving to another school in the UK or being home educated.
"We work closely with The Children Missing from Education (Scotland) (CMES) Service to ensure all cases are investigated thoroughly."
A City of Edinburgh Council spokesman said: "We have very strict protocols in place for identifying children who may be, for whatever reason, not receiving an education.
"These include checks by their schools, the involvement of education welfare officers and other local authorities, right through to the Scottish government and Interpol.
"Although there are often quite straightforward reasons why children may not be at school, it's important we carry out all the checks we can to ensure their welfare."
A spokeswoman for Glasgow City Council said: "Glasgow has a very transient population with approximately a class of 25 in and out of the city each week.
"We will do all that we can to follow up on any child that moves out of the country and have Slovakian case workers in Govanhill who do as much as they can to trace families. A number of families move around and don't stick to term dates either.
"Asian families can go off on holidays and not return. Again, we will do all that we can to make sure they are in education in the new country."