The number of migrants who died or went missing trying to cross the Mediterranean this summer was three times the number seen in the same period last year, the UN said Friday.

Between June and August, at least 990 people died or went missing in the dangerous central Mediterranean route between northern Africa and Europe, compared to 334 deaths over the same months in 2022, the UN's children's agency UNICEF said.

The agency gave no separate number for children dying during the crossings, but said that 11,600 unaccompanied minors had been among the migrants trying to get to Italy on makeshift vessels between January and September, up 60 percent from the first nine months of 2022.

"The Mediterranean has become a cemetery for children and their future," UNICEF coordinator Regina De Dominicis said.

"The tragic toll of children dying in search of asylum and security in Europe is the result of political choices and a defective migration system," she said.

According to the UN High Commissioner for Refugees, 2,500 migrants died or went missing in the Mediterranean between January 1 and September 24, 50 percent more than in the same period last year.