Bulgarian border police have detained 29 illegal immigrants and two 17-year-old traffickers after they entered the country from Greece, the national Prosecutor's Office said in a statement on Thursday.

The group was arrested on Wednesday near the village of Mezek, some 290 km southeast of Sofia, the statement said.

The foreigners, seven of them children, were all Iraqi citizens, it said.

Bulgaria is located on a migrant route to Central and Western Europe. According to official data, the Ministry of Interior arrested 2,989 illegal immigrants in 2017.