About 350,000 migrants and refugees have arrived in the European Union so far this year, a sharp decline from 2015 when more than 1 million people arrived, according to the EU border control agency.

Fabrice Leggeri, executive director of the Frontex border agency, was quoted on Saturday as saying about 180,000 people arrived via Turkey and the eastern Mediterranean, while 170,000 reached the continent across the central Mediterranean route from Libya and Egypt.

Missing refugees remain uncounted

Leggeri told German daily Ruhr-Nachrichten a deal between the EU and Turkey reduced the number of refugees and migrants coming from the east, but migration from northern Africa rose 30 percent.

Earlier, the International Organization of Migration (IOM) said that 4,812 people have died on the Mediterranean so far this year - a record number.

That is about 1,200 more than last year between January to the end of November.

According to the IOM, 7,189 migrants and asylum seekers have died so far this year around the world, notably in Central America. 

That is an average of 20 deaths each day, with the IOM predicting that another 200 to 300 will die en route to safer lands before the year is over.

IOM spokesman Leonard Doyle told Al Jazeera that the casualty numbers are "undoubtedly an underestimate".

"This is the numbers we have of people who are reported to have died, but there are many more who have died lonely deaths, by themselves, in the deserts and in the oceans," said Doyle.

He added that the nature of the crisis makes it difficult for any organisation or government to keep an accurate count of the dead and missing.

"They [migrants and refugees] are leaving in a clandestine way, they're leaving without papers, and they're leaving in small and dangerous boats. Quite often these boats sink without a trace and nobody actually knows about them," said Doyle. 

Source: Al Jazeera and news agencies