Over 150 migrants rescued off Greece's Crete in recent days

On Friday alone, 131 were rescued in two operations carried out by vessels operated by Frontex, the EU's border control agency, ANA said.

On Saturday, a passing oil tanker was directed to save 33 migrants from a small boat.

The migrants were to be taken to centres set up on the islands of Lesbos and Samos, and from there possibly on to other centres on the Greek mainland, the country's migration ministry said.

Crete, and the nearby tiny island of Gavdos, lie on a maritime path used by migrants on boats setting off from Libya in bids to reach Europe.

The inflow has stoked tensions among some Greek residents.

"Serious incidents" broke out Saturday night in a temporary centre for asylum-seekers in Sintiki, in northern Greece, state television reported on Sunday, adding that police reinforcements were sent there.

The Greek government said 14 people were arrested and five foreigners were hurt when a group of people threw stones at police.

It said that the group cut the wire fence around the centre and 41 people "escaped" but 17 were later arrested.