Coastguards in Tunisia have retrieved the bodies of 21 sub-Saharan migrants and rescued 50 after their boat sank off the port city of Sfax, authorities said on Monday.

-Twenty-one bodies of migrants were recovered after their boat was shipwrecked on July 4, and 50 were rescued- National Guard spokesman Houcem Eddine Jebabli told AFP.

He said the migrants, all from sub-Saharan Africa, had been trying to reach Europe.

The spokesman said four boatloads of migrants had sunk since June 26 after setting off from Sfax, with the bodies of 49 people recovered and 78 rescued.

On Saturday, a boat that had set off from neighbouring Libya the previous day with 127 people on board went down off Zarzis on Tunisia's southern coast.

The country's Red Crescent said 43 migrants were missing after the accident.

The defence ministry said the navy had rescued "84 illegal migrants of various nationalities" including from Bangladesh, Chad, Egypt, Eritrea and Sudan.

Tunisia and neighbouring Libya are key departure points for migrants, many from sub-Saharan Africa, who attempt the dangerous crossing from the North African coast to Europe, particularly Italy.

In early May, the UN's refugee agency UNHCR said that at least 500 people had died trying to cross the central Mediterranean this year, more than triple the 150 in the same period of 2020.