Sofia police have carried out a specialized operation targeting migrants in several parts of Bulgaria's capital, officials say.

As many as 562 people had their documents checked by police.

The operation, which involved inspections at hotels, hostels "and other accommodation centers" among other sites, was planned and confirmed by Chief Prosecutor Sotir Tsatsarov, the Interior Ministry's press office reported on Friday.

As many as 267 places were inspected "to establish [the presence of] illegally dwelling foreigners".

Ten Bulgarians and three foreign nationals with no proper documents were detained by police to further establish their identity.