Serbian security officials say they have removed dozens of what they call illegal migrants, including unaccompanied minors, from the streets of Belgrade and placed them in migrant centers.

“The migrants have been provided with proper conditions, as well as all protection under the laws of the Republic of Serbia and in accordance with international standards,” Milenko Nikic, the coordinator of the action and an adviser to Labor Minister Zoran Djordjevic, said in a statement on February 2.

It said the action — part of a plan to address the thousands of migrants residing in the country — was carried out with incident.

Thousands of migrants and refugees have been stuck in Serbia after tighter border controls shut down the so-called “Balkan route” into the European Union in 2015.

Hungary closed its border completely in 2015 and since then has allowed only 10 people per day, mostly families, to enter from Serbia.

According to Serbian aid groups, about 4,000 people live in official migrant camps in Serbia.

But the groups estimate that a further 500 people live outside these facilities, fearing they could be deported or be prevented from crossing into the EU, via Hungary or Croatia, if the chance arises.