ATHENS -  Greece's port police said Monday at least 16 people including women and children have died in a suspected migrant boat sinking off the Aegean island of Lesbos.

The bodies of six women, a child and two men were recovered in Greek waters, while the Turkish coastguard found the bodies of another six men and a child, the Greek coastguard said in a statement. Greek authorities had received no distress call prior to finding the bodies, a coastguard spokeswoman said. Weather conditions in the area are mild. Authorities added that as well as the deceased there were five Bangladeshis, three Pakistanis, three Iraqis and three Iranians in the van.

Searches continue after a pregnant woman, one of two survivors, told officials that there had been a total of 25 people on board.

According to the two African survivors, the boat capsized Sunday night, the UN refugee agency (UNHCR) said.

Greece's Aegean Sea islands are a primary transit point for refugees and migrants seeking to reach Europe from Turkey.

In 2015 and 2016, more than 1,000 refugees and migrants perished in the dangerous sea crossing. Over a million people have landed in Greece since 2015, many of them fleeing civil war in Syria.

Another entry point is in northern Greece near the Turkish border where there was another accident involving migrants on Monday.

A van carrying 15 illegal migrants overturned in a high-speed chase with police, killing a 35-year-old Iranian on board, Greek police said in a statement.

Three migrants and the driver of the van, a 29-year-old Moldovan, were injured and hospitalised, police said.

There have been fewer of these deadly accidents this year following an accord between the European Union and Turkey reached in March 2016 that has curtailed the influx of migrants.

According to UNHCR, around 4,900 people have tried to make the crossing from Turkey to Greece since the beginning of this year, compared with 173,450 reported arrivals in 2016.