Two people have been arrested in Serbia on suspicion of helping to smuggle Cubans to Spain as part of a global crime ring, police said.
They were held as part of a lengthy investigation also involving Spain, Interpol and Europol, Serbian authorities said in a statement.
Some 18 more suspects have been detained in Spain.
The Serbian suspects are accused of organising the illegal transfer of at least 53 people to neighbouring countries – North Macedonia or Bosnia – and on to Spain, the statement said.
Serbia, a southeastern European nation on the Balkan peninsula, is at the heart of a key land route for migrants trying to reach the European Union (EU).
The country in April revoked a visa-free travel arrangement with Cuba after reports of Cubans heading towards Spain and other EU countries after first coming to Serbia as tourists.
Serbia also imposed visas earlier this year for the citizens of Burundi, Tunisia and India for the same reason and under pressure from the EU, which is seeking to curb migration into the 27-nation bloc.
