ATHENS - At least eight people drowned when a boat carrying migrants from Turkey sank off the Greek island of Kos, the coastguard said Tuesday.

They were the latest of nearly 3,500 deaths at sea this year among people making desperate bids to flee war and poverty and to reach Europe, according to UN figures. The coastguard recovered six bodies from the water, while divers found the remains of two others trapped in the sunken boat. Seven survivors from the same vessel said up to five other migrants were still missing. Rescue efforts were under way Tuesday morning, the coastguard said.

The boat, which came from nearby Turkey and which capsized overnight, was spotted by the crew of a Finnish ship participating in operations by Frontex, the EU's border security agency.

A three-year-old child died on Saturday off Greece's Chios island further north when the motor of the vessel he was travelling in exploded. More than 800,000 migrants, mostly fleeing war and persecution in Syria, Iraq and Afghanistan, have crossed the Mediterranean this year to reach Europe.

Meanwhile, the United Nations on Tuesday called on states not to "backtrack" on pledges made to host migrants and refugees, including from Syria, in the wake of the attacks in Paris. "We are concerned about the reactions from some states to end programmes being put in place, backtracking from commitments made to manage the refugee crisis," said UN refugee agency spokeswoman Melissa Fleming. "Refugees should not be turned into scapegoats and must not become the secondary victims of these most tragic events," Fleming added, after some EU states indicated they would take a hard line on the migrant crisis following the attacks.

She described as "disturbing" rhetoric from some countries suggesting they might walk back on previously made commitments.

"What's being threatened is an EU plan to manage the arrival of so many people... We need all the countries in Europe to be on board," Fleming said.

European populist and far-right leaders have seized on the miliant attacks in Paris to demand the continent stem the record migrant influx.

Hungary's parliament on Tuesday gave Prime Minister Victor Orban the green light to challenge in court a quota system on taking in migrants, which was previously agreed by EU governments.

France's anti-immigration National Front leader Marine Le Pen called for an "immediate halt" to new arrivals, while Germany's xenophobic PEGIDA movement drew thousands to their latest anti-Islam rally.

Poland's new right-wing, eurosceptic government, which was sworn in Monday, signalled it would take a harder line on migrants, while honouring previously agreed EU commitments.

Some politicians voicing anti-migrant rhetoric have pointed to the discovery of a Syrian passport near the body of one of the Paris suicide attackers, with French prosecutors saying his fingerprints matched those recorded in October in Greece, the start of the European migrant trail for many.