The route from Libya to the tiny Italian island of Lampedusa has become the deadliest migrant route in the world.

If the deaths are confirmed, it would bring to about 1,600 the number of migrants who have died since the start of the year in attempting to make the passage from Libya to Italy. For all of 2014, nearly 3,200 died attempting the passage, according to figures from the International Organization for Migration. According to the IOM, if the 700 deaths are confirmed, it would be one of the highest-ever migrant death tolls in a single incident.

Last year, about 170,000 African and Middle Eastern migrants arrived in Italy using that passage, with a total of nearly 300,000 arrivals in all since the start of 2011.

Conflicts and poverty in African and the Middle East have driven people to attempt the dangerous journey in ever greater numbers.