Europe border patrol: On board boat off Greece island of Lesbos

After the Greek government increased controls on the land border with Turkey, Greece's islands have seen a surge in immigrants attempting to enter the country.

Lesbos in the north-east Aegean Sea now has the highest number of migrant arrivals.

The EU's border agency, Frontex, is working with Greek authorities to patrol the borders, and there is pressure on EU leaders to boost its powers.

Our correspondent Mark Lowen travelled with a night-time Frontex patrol around Lesbos.