More than 18,000 child migrants have gone missing after arriving in Europe in the past three years, an investigation found.
Data was gathered by Lost in Europe, a cross-border journalism project, which warned that missing children were vulnerable to being exploited by human traffickers and drugs gangs.
The true number is likely to be higher than the estimated 18,292, because figures were unavailable for some countries, including France.
The data also did not include the UK, which last month set out plans to overhaul asylum laws and bring in robust age checks to prevent adult migrants posing as children.
Many of the disappearances were reported in Mediterranean countries on the front line of European migration, including Italy, which accounted for nearly 6,000 of the total.
More than 2,000 migrant children were reported missing in Greece from 2018 to 2020, and about 1,900 in Spain.
There were about 2,600 such cases in the Netherlands and more than 1,000 in Belgium, where police last month launched a major operation against drug traffickers.
Disappearances were reported across the continent from Ireland to Malta.
The breakdown was published by Dutch broadcaster VPRO, one of several European news outlets that reported the findings in collaboration with Lost in Europe.
Reports of missing children continued during the year of the pandemic, with more than 5,500 cases registered in 10 countries during 2020.
"This number might be a lot higher, since a solid record of these cases is missing," Lost in Europe said.
Unicef, the UN children’s fund, warned last year that Covid-19 threatened to exacerbate the "already precarious existence" of migrant children who would struggle to access health care.
It said that displaced children were also more likely to face xenophobia and discrimination because of misinformation around the spread of coronavirus.
Separate EU findings showed that the most common countries of origin of missing children in Europe were Afghanistan, Morocco and Algeria.
Tunisian children were the largest group among missing unaccompanied minors in Italy in 2018 and 2019.
The vast majority across Europe were boys, and most were aged over 15.
EU warns of risks to migrant children
The report comes after the European Commission last month published a new “strategy on the rights of the child”, which said that young refugees were “very often exposed to risks of abuse”.
The risk was particularly high when children travelled without their parents or became separated from their families, the EU report said.
But it said there were also dangers when children were “obliged to share overcrowded facilities with adult strangers”.
Around 30,000 children are estimated to live in the Al Hol refugee camp in Syria.
The EU said children should only be put in detention facilities “as a last resort and for the shortest appropriate time”.
Advocacy group Missing Children Europe said it welcomed the EU’s call for “viable and effective, non-custodial measures”.
It said it would monitor the EU on the issue to “make sure that these commitments do not remain words on paper”.
In 2019, about 12 per cent of global migrants – some 33 million – were estimated to be children.
The UN’s International Organisation for Migration previously said that children in Europe sometimes slipped under the radar and avoided accessing health or education services in order to evade detection.
In addition to avoiding immigration authorities, children sometimes went to ground because of pressure to send money home or to repay debts incurred on their journey to Europe, the IOM said.
Migrant children struggling to support themselves could become “dependent on work performed in informal and dangerous settings”, it said.
Others were prone to leaving refugee shelters because of poor living conditions and their inability to access education.