The migrant rescue ship Ocean Viking saved 46 people in distress off the coast of Libya on Friday who were trying to reach Europe in a fibreglass boat, the humanitarian NGO said on Twitter.

Those rescued include four single women, a four-year-old girl travelling with her father and around ten unaccompanied minors, according to SOS Mediterranee.

The survivors are "now being cared for", the group said, adding they were mostly from Eritrea, Ethiopia and Sudan.

The central Mediterranean is the most dangerous migration route in the world, according to the International Organisation for Migration.

The UN agency has estimated that since the beginning of 2023, 1,728 migrants have disappeared there, compared to 1,417 for the whole of 2022.

Frontex, the EU's border patrol agency, says boat crossings across the central Mediterranean constitute the principal route for irregular migrant entries to Europe.

Crossings leaving North African countries including Tunisia and going to EU nations Italy and Malta "more than doubled" between January and May this year, compared with the same period in 2022, it says.

In June an overcrowded fishing trawler carrying hundreds of migrants sank off the coast of Greece, in one of the worst such tragedies in years.

Some 104 people were rescued and 82 bodies were recovered, but as many as 560 others on board may have perished, by some estimates.