The Coast Guard rescued five people and was searching for about 20 people who were not yet identified, the official said.
“The ship sank about six miles off the coast of Sfax. Twenty bodies were recovered, another five were rescued and all came from sub-Saharan Africa,” said security chief Ali Ayari.
He added that about 45 people were on the boat when it sank.
The coastline near the port city of Sfax has become an important starting point for people fleeing conflict and poverty in Africa and the Middle East and seeking a better life in Europe.
Countries such as Italy and Malta have seen an increase in maritime arrivals from Tunisia this year – where high unemployment and uncertain socio-economic conditions have motivated migration – and Libya, where conflict and war were a major factor, according to data United Nations High Commissioner for Refugees (UNHCR).
Thursday’s deaths add to the already long list recorded this year, even with travel restrictions on the Covid-19.
According to IOM, the ship was reported to be carrying more than 120 people, including women and children.
Soda called for a change in the “unfeasible approach of Libya and the Mediterranean, which includes ending returns to the country and establishing a clear landing mechanism followed by the solidarity of other states.”
“Thousands of vulnerable people continue to pay the price of inaction both at sea and on land,” he said.
According to IOM, migration-related deaths are often unrecorded and unrecorded, which also said the pandemic has made it difficult to collect this data.
CNN’s Emma Reynolds and Sharon Braithwaite contributed to this report.