TUNIS -- Forty irregular immigrants from sub-Saharan African countries have died after their boat capsized off the eastern coast of Tunisia during an attempt to cross the Mediterranean Sea toward Europe, private radio station Mosaique FM reported Wednesday.

The incident took place early Wednesday morning near the coastal city of Salakta in the central-eastern province of Mahdia, according to Mosaique FM.

Walid Chaterbi, spokesperson for the Court of First Instance in Mahdia, said the victims included several infants. He added that 30 other passengers were rescued by units of the Tunisian maritime guard.

The public prosecutor's office in Mahdia has launched an investigation into the circumstances of the shipwreck.

Located about 130 km from the Tunisian coast, the Italian island of Lampedusa is a frequent destination for migrants from sub-Saharan Africa seeking to reach Europe via the Mediterranean.