They are subjected to a medical examination if there is any doubt about their age. 250 such tests have been carried out so far this year. The majority of those tested were found to be older than 18.
On Thursday, the Chamber of Representatives passed a bill containing rules on how un-accompanied minors that have asked for asylum should be looked after.
Around 2,500 unaccompanied minors ask for asylum in Belgium each year. The vast majority of them are male.