The death toll from a migrant boat sinking off Tunisia has risen to 11, with rescue teams continuing to search for people still missing, Tunisian authorities said.

The boat, carrying 15 Tunisian migrants, sank while travelling towards Italy, one of the main destinations for people attempting the dangerous Mediterranean crossing.

Tunisian coast guard teams initially recovered eight bodies before finding three more during continued search operations. One passenger was rescued alive after drifting at sea for around 48 hours.

Three people remained missing, according to the National Guard.

The passengers included seven members of one family and a man travelling with his pregnant wife, all from the Ben Guerdane area in southeastern Tunisia, Reuters reported.

The disaster has caused anger in Ben Guerdane, where residents staged protests demanding that authorities intensify efforts to find those still missing.

Police used tear gas to disperse some demonstrators, according to reports.

The sinking highlights the continuing dangers faced by people attempting to cross the Mediterranean in small and often poorly equipped boats.

Tunisia has become a major departure point for migrants heading towards Italy, while European governments have sought to reduce the number of irregular crossings through cooperation with North African countries.

Rights groups have criticised aspects of those policies, arguing that efforts to prevent departures must also address the safety and rights of migrants.

Search operations for the remaining missing passengers were continuing.