The UNHCR has said more than 700,000 migrants and refugees have traveled to Europe by boat so far this year. More than 3,210 have lost their lives in the attempt to reach the EU.
Greece has borne the brunt of the migrant arrivals, with some 562, 355 people - the vast majority of them fleeing conflict and poverty in the Middle East and Africa - making the dangerous Mediterranean crossing to the country so far in 2015, the UN's refugee agency said on Tuesday.
Italy has also received some 140,000 people arriving by boat on its shores, the statement from the United Nations High Commissioner for Refugees (UNHCR) said. Several thousand more have reached other European countries, notably Spain.
The number of people seeking shelter in Europe has grown continually throughout the year, with October seeing the greatest number of arrivals, despite worsening weather conditions that are increasing the perils of the voyage. Some 170,000 migrants have reached Europe this month by sea, as compared with fewer than 40,000 in the same month last year.
The UN said children have made up 20 percent of the sea arrivals, with men being in the majority by far at 65 percent, compared with 14 percent women.
More than half from Syria
More than half of the refugees were from Syria, with Afghanistan and Iraq as other major countries of origin. Altogether 85 percent of people were from the 10 countries that the UNHCR says produce the most refugees.
In addition to the three countries already mentioned, they include Eritrea, Nigeria, Pakistan, Somalia, Sudan, Gambia and Bangladesh.
The arrival of hundreds of thousands of migrants has resulted in Europe's worst migration crisis since World War II, and the flow shows no sign of abating, with the International Organization for Migration saying that 5,239 people arrived in Greece on Saturday and 4,199 on Sunday.