At least 65 migrants drowned on Friday when their boat capsized in the Mediterranean Sea off the Tunisian coast after they had left Libya hoping to reach Europe, the UN refugee agency UNHCR said.

The state-run Tunis Afrique Presse agency gave a death toll of at least 70 people. It was one the deadliest shipwrecks involving migrants trying to reach Europe this year.

“This is a tragic and terrible reminder of the risks still faced by those who attempt to cross the Mediterranean,” UNHCR Special Envoy for the Mediterranean Vincent Cochetel said in a statement.

In the first four months of 2019, 164 people are known to have died on the route, a smaller number but higher death rate than in previous years, with one dying for every three who reach European shores, UNHCR said.

UNHCR said the sunken boat had taken to the sea on Thursday from neighbouring Libya, where renewed warfare between rival factions has gripped the capital Tripoli in the past five weeks.

The Tunisian navy brought 16 survivors to the coast at Zarzis, where one was immediately taken to hospital and the others awaited permission to disembark, UNHCR said.

The Tunisian agency said the boat had sunk 40 miles off the coast of Sfax, south of the capital Tunis and that fishing boats had rescued the survivors.

Tunisia’s defence ministry said the boat had left from the Libyan port of Zouara aiming to reach Italy. Navy units have recovered only three bodies so far, it said in a statement.

Libya’s west coast is a main departure point for African migrants hoping to reach Europe by paying human traffickers, though numbers have dropped due to an Italian-led effort to disrupt smuggling networks and support the Libyan coast guard.

Earlier on Friday, UNHCR spokesman Babar Baloch said the United Nations had repeatedly voiced its concerns about the lack of boats to pick up migrants and refugees fleeing from “the horrendous and horrible situation” in Libya. It called on governments to step in.

Although the fighting in Libya has made the situation more difficult for people-trafficking rackets, international aid officials have warned that it could also prompt more Libyans to flee their country.

It was not immediately known from which countries the migrants involved in Friday’s tragedy were from.

According to UN agency the International Organisation for Migration (IOM), 2,297 migrants died or went missing in the Mediterranean last year out of a total of 116,959 people who reached Europe by sea.

Some 117 migrants who left Libya in a rubber dinghy in January went missing and most remain unaccounted for, according to the IOM.