A total of 8,565 migrants died on land and sea routes worldwide last year, a record high since the UN migration agency began tallying deaths a decade ago.

The International Organisation for Migration (IOM) said the biggest increase in deaths last year was on the treacherous Mediterranean Sea crossing, with a rise to 3,129 from 2,411 in 2022.

However, that was well below the record 5,136 deaths recorded on the Mediterranean in 2016 as huge numbers of Syrians, Afghans and others fled conflicts toward Europe.

The IOM said the total number of deaths among migrants in 2023 was nearly 20% more than in 2022.

It said most of the deaths last year, about 3,700, came from drowning.

The Geneva-based migration agency cautioned that the figures likely underestimate the real toll, and factors such as improved data collection methods play a part in its calculations.

IOM deputy director general Ugochi Daniels said: “Every single one of them is a terrible human tragedy that reverberates through families and communities for years to come.”

Overall, the biggest jump in deaths in recent years was in Asia, where more than 2,000 migrants died compared to an annual average of under 1,000 since 2014. The IOM said 2,138 migrants died in Asia last year, 68 more than in 2022.

The rise in Asia last year was primarily because of increased deaths among Afghans fleeing to places like neighbouring Iran and among Rohingya refugees on maritime routes, IOM spokesperson Jorge Galindo said in an email.

The IOM said a record number of deaths also occurred in Africa last year – 1,866 – mostly in the Sahara Desert and along the sea route to the Canary Islands.

The agency cited difficulties in data collection in remote areas, such as in the dangerous “Darien Gap” in Panama, where many migrants pass from South America on their way north.

The IOM’s “Missing Migrants” project, which tallies the figures, was set up in 2014 after a surge in deaths in the Mediterranean and an influx of migrants on the Italian island of Lampedusa off Tunisia.