Massive Syrian refugee influx
Greece replaces Italy as principal European gateway for migrants as arrivals from Syria and Afghanistan drive 408% year-on-year increase.
Greece received almost 100,000 seaborne migrants in the first six months of 2015.
UN data shows that Greece received more boat arrivals than any other European country in the first half of 2015, with about 101,000 migrants arriving on Greek shores between 1 January and 17 July, according to the UNHCR, the UN refugee agency.
Migrant flows usually increase over the summer months, when the Mediterranean sea is calmer and boat crossings are less risky. More than 31,000 migrants arrived in Greece by boat in June alone, the data showed. In contrast, the country received a relatively modest 3,452 migrants in June 2014.
The number of migrants arriving on Greek shores soared by 408% over the first six months of 2015 compared with the same period last year, driven in large part by a surge in Syrians fleeing the brutal war in their country.
The crisis is set to escalate in the months to come, following the recent Turkish military assault on targets inside the Syrian border.
Turkish Prime Minister Ahmet Davutoglou said "this is a war against jihadists, Kurds and leftist militants and it's not going to stop".