At least 40 migrants from sub-Saharan African countries have died after their boat sank off the coast of Tunisia on Wednesday, in one of the deadliest maritime tragedies in the region this year, an official said.

The boat, carrying about 70 migrants, sank near the coastal city of Mahdia, the official added.

Tunisia has become a key transit country for migrants fleeing conflict and poverty in search of better opportunities in Europe.

The latest incident highlights the ongoing risks faced by migrants and the growing pressure on North African countries to manage irregular migration routes.