ZAGREB (Reuters) - Croatia received on Friday the first group of migrants - four Eritreans arriving from Italy - under a European Union relocation scheme which has prompted criticism and resistance from some ex-communist member states of the bloc.

Croatia is due to receive 1,583 migrants under the relocation scheme agreed last September which envisages the transfer of some 160,000 people in total from Greece and Italy.

Only a very small number of migrants has so far been relocated due to the resistance of some member states, especially in central Europe, that argue it will be difficult to integrate them. Most migrants are Muslims from the Middle East.

Most migrants are Muslims who have fled conflicts or poverty in the Middle East, Afghanistan and Africa.

"We'll do everything to make your life easier and to relieve the troubles which made you venture on this journey," Interior Minister Vlaho Orepic told the migrants on their arrival.

They will be housed temporarily in a reception center for asylum seekers in the capital Zagreb.

Some 650,000 people passed through Croatia from last September to March on the so-called Balkan route used by the migrants, largely from Syria, who headed toward western Europe, especially Germany.

The route was largely shut down in March after a series of border closures.

(Reporting by Igor Ilic; Editing by Gareth Jones)