Discarded life jackets line the rocky shores of Lesbos, Greece on September 10, 2015.
Discarded life jackets line the rocky shores of Lesbos, Greece on September 10, 2015.
ANGELOS TZORTZINIS/AFP/AFP/Getty Images
A refugee sleeps near the port of Mytilini on September 9, 2015 in Lesbos. He's one of thousands of migrants who have landed on the island's shores, after boarding inflatable boats from Turkey.
A refugee sleeps near the port of Mytilini on September 9, 2015 in Lesbos. He's one of thousands of migrants who have landed on the island's shores, after boarding inflatable boats from Turkey.
Eric Thayer/Getty Images Europe/Getty Images
Long queues form as refugees wait to receive food in a park near the port of Mytilini, Lesbos. Many arrive wet, hungry and tired after paying huge amounts of money to risk their lives on small, crowded boats.
Long queues form as refugees wait to receive food in a park near the port of Mytilini, Lesbos. Many arrive wet, hungry and tired after paying huge amounts of money to risk their lives on small, crowded boats.
Eric Thayer/Getty Images Europe/Getty Images
Local relief agencies work to feed the migrants before they make their onward journey. The U.N. says approximately 50 boats of migrants land on Lesbos each day, depositing from 1,500 to 3,000 new immigrants.
Local relief agencies work to feed the migrants before they make their onward journey. The U.N. says approximately 50 boats of migrants land on Lesbos each day, depositing from 1,500 to 3,000 new immigrants.
Eric Thayer/Getty Images Europe/Getty Images
Traffickers charge each migrant $1,350 to board inflatable boats from Turkey. Often they're overcrowded, and many take on water along the way. This boat arrived on September 9.
Traffickers charge each migrant $1,350 to board inflatable boats from Turkey. Often they're overcrowded, and many take on water along the way. This boat arrived on September 9.
ANGELOS TZORTZINIS/AFP/AFP/Getty Images
Many of the migrants have cell phones, loaded with the phone numbers of Greek rescue authorities so they can come to their aid. Facebook pages also give migrants advice on what to do when they arrive.
Many of the migrants have cell phones, loaded with the phone numbers of Greek rescue authorities so they can come to their aid. Facebook pages also give migrants advice on what to do when they arrive.
ANGELOS TZORTZINIS/AFP/AFP/Getty Images
A woman cries after arriving on the island of Lesbos, after crossing the Aegean Sea from Turkey on a dinghy on September 10.
A woman cries after arriving on the island of Lesbos, after crossing the Aegean Sea from Turkey on a dinghy on September 10.
ANGELOS TZORTZINIS/AFP/AFP/Getty Images
Migrants buy tents to make their journey more comfortable. A Facebook page for refugees even tells them what sort to buy and where. Here, a migrant looks out to sea.
Migrants buy tents to make their journey more comfortable. A Facebook page for refugees even tells them what sort to buy and where. Here, a migrant looks out to sea.
ANGELOS TZORTZINIS/AFP/AFP/Getty Images
Migrants slash boats, dump life vests on shores of Lesbos, Greece
CNN  — 

Eight people have died after a “plastic boat carrying refugees or migrants” overturned near the Greek island of Kos on Tuesday, the Greek coast guard said.

Two of the bodies were still trapped inside the overturned vessel, they added. Seven others were rescued.

It is not known how the boat overturned or the nationalities of the passengers, the coast guard said.

Greece has become the main gateway to Europe for tens of thousands of refugees and migrants fleeing war and economic hardship.

Read: Seeking refuge – Migration Crisis

CNN’s Gul Tuysuz and Arwa Damon reported from Leros, Greece, Tiffany Ap wrote from Hong Kong.