More than one million refugees and irregular migrants reached Europe by sea and land this year, nearly five times the figure in 2014, the International Organisation for Migration (IOM) has said. 

The number of refugees and migrants that reached Europe since the beginning of 2015 was 1,005,504 after 4,100 people arrived in Greece on Monday, IOM said.

Of the total number, 816,752 refugees arrived by sea in Greece and only 3% arrived by land. 

Syrians constituted the highest number of asylum-seekers, while people from Iraq and Afghanistan also arrived in huge numbers in Europe. 

Around 455,000 refugees arrived from Syria, while over 186,000 came from Afghanistan, according to IOM.

Last week, on International Migrants Day, the organisation had said at least 3,695 people have died while trying to reach Europe this year. 

Scores of children, including infants, have drowned while attempting to reach Greece from Turkey on inflatable rubber dinghy boats that sank midway. 

The image of two-year-old Aylan Kurdi lying dead on a Turkish shore after he was washed up in September sparked global outrage about the current refugee crisis, the worst since the World War II.