Some 250 asylum-seekers have blocked a busy northern Greek highway, in a second day of protests against overcrowding and poor conditions in the nearby camp they are housed in.

The peaceful protest by mostly Kurdish migrants at Diavata, on Thessaloniki's western outskirts, lasted an hour and caused major traffic jams.

The Diavata camp's prefabricated homes can house 750 people, but its population has grown to 1,850 amid increased immigration flows from Turkey. New arrivals sleep in tents or on the ground.

Greek officials are reopening camps built after the immigration crisis of 2015, in which more than a million people arrived on their way to Europe's affluent heartland.

Most of these camps were later closed and their occupants moved to flats in Greek cities or relocated to other European countries.