At least 20 migrants from Africa died when their boat sank off Tunisia on Thursday as they tried to cross the Mediterranean to the Italian island of Lampedusa, a Tunisian security official told Reuters.
He said the coastguard rescued five people, and they were searching for about 20 others who were on board the boat.
The coastline near the Tunisian port city of Sfax has become a major departure point for people fleeing conflict and poverty in Africa and the Middle East and searching for a better life in Europe.
"The boat sank about six miles from the coast of Sfax," the security official, Ali Ayari, said.
Around 45 people were on the boat when it sank, he added.
War-torn Libya has also become a key embarkation point for migrants, mostly from sub-Saharan Africa, attempting death-defying voyages to Europe to flee conflict and poverty at home.