Survivors have said the boat had set off off the Libyan coast.
Over 40 people are missing after a boat carrying migrants crashed off the coast of Tunisia, the Tunisian Red Crescent said on Saturday.
According to the organization, more than 80 people were rescued. There were nearly 130 migrants in the boat when it sank on Friday night.
Survivors have said the boat had set off off the Libyan coast, a Red Crescent spokesman said.
There were migrants from Bangladesh, Chad, Eritrea and Sudan, among others, the Tunisian Ministry of Defense said.
Migrants rescued from the sea are between the ages of three and 40.
According to the Ministry of Defense, the boat had left the port of the city of Zuwara in northwestern Libya on Monday-Tuesday night.