The bodies of 120 migrants have washed up on the shores of Libya in the past 10 days, not from previously known shipwrecks in the Mediterranean, the International Organization for Migration (IOM) said on Tuesday.

A total of 4,027 migrants or refugees have died worldwide so far this year, three-quarters of them in the Mediterranean while trying to reach Europe, IOM spokesman Joel Millman told a briefing.

That represents a 35 percent increase on the global toll during the first seven months of 2015, he said.