The first 30 refugees to be relocated from Greece have boarded a plane in Athens bound for Luxembourg.

The six families from Syria and Iraq who left Greece on Wednesday mark the start of a program seeking to relocate refugees who have arrived in Greece from nearby Turkey to other European Union countries without them having to make the arduous and often dangerous overland journey across the Balkans on foot.

More than 600,000 refugees and migrants have arrived in Greece so far this year, most of them in the last few months.

Hundreds have died as their overloaded and unseaworthy boats and dinghies overturned or sank in the Aegean. Another four people — two children and two men — drowned Tuesday night.