Thousands of unaccompanied children and teenagers have reportedly disappeared in Germany over the past year amid concerns that they might have fallen into the hands of criminals and human smugglers.

The German news organization Funke Mediengruppe reported on Monday that 5,835 refugee minors from countries in Africa, the Middle East and Central Asia went missing in the Western European country in 2015, of whom 555 are under the age of 14.

The majority of the missing and unaccompanied minors were from Afghanistan, Syria, Eritrea, Morocco and Algeria.

This is while officials in Berlin have no indications of their whereabouts.

German Interior Ministry spokesman Johannes Dimroth confirmed media reports that the government had recently informed parliament about the disappearance of nearly 6,000 refugee children.

Dimroth added that the actual number of the missing children could be even slightly higher than the current statistics. He, however, could not give reasons for their disappearance.

Berlin has come under fire by politicians of the Green Party for not taking serious actions to address the problem.

German Federal Ministry for Family Affairs spokeswoman Verena Herb, however, said the government is very sensitive about the problem, and has recently taken new legal and practical measures to address it.

“We cannot rule out that these children and teenagers might fall into the hands of criminals,” Herb noted.

Children sit in a tent in the makeshift camp at the Greek-Macedonian border near the village of Idomeni, where thousands of asylum seekers and refugees are stranded on March 7, 2016. ©AFP

She said new reception centers will be opened especially for unaccompanied children and teenagers, and federal states will improve the exchange of information as well as improving the registration system.

German authorities believe that a proportion of the disappeared refugee children could have been taken by their relatives in Germany or elsewhere in Europe, and in many cases these are not reported to officials and not reflected in statistics.

In February, the EU police agency Europol said more than 10,000 unaccompanied refugee children have gone missing after arriving in Europe over the past 18-24 months

Several members of the European Parliament said late last month that missing underage refugees might be victims of criminal organizations involved in sex, slavery or organ trafficking.

Europe is facing an unprecedented influx of refugees, who are fleeing conflict-ridden zones in Africa and the Middle East, particularly Syria.

Many blame major European powers for the unprecedented exodus, saying their policies have led to a surge in terrorism and war in those regions, forcing more people to flee their homes.