Fifteen migrants were arrested on Sunday by police officers in the region of Blagoevgrad, Southwestern Bulgaria, the Interior Ministry reports.

The migrants were spotted in the morning as they were moving between the villages of Levunovo and Kulata, the latter being on the border between Bulgaria and Greece.

They were carrying no identity documents with them, and their country of origin is yet to be established, but some of them claim to be from Afghanistan, Focus Radio quotes police officials as saying.

Their direction was not immediately clear.

However, dozens of migrants are detained every week after crossing into the country from Turkey and sometimes Greece, heading for Western Europe. Serbia has accused Bulgaria of not applying good enough border controls and letting hundreds of people leave through its western border.