At least 45 illegal immigrants and refugees have died when the engine of their vessel exploded off the coast of Libyan Zuwara, the UN refugee agency reported on Wednesday.

In a joint statement, the United Nations High Commissioner for Refugees (UNHCR) and the International Organization for Migration (IOM) expressed their profound grief over the tragic incident that occurred last Monday, saying it was the deadliest shipwreck off Libya this year.

There were more than 80 people on board the vessel, predominantly from Senegal, Mali, Chad, and Ghana, and among them were five children, according to some 37 survivors who were rescued by local fishermen.

The UN agencies called on governments to review their approach to the situation and to step up search and rescue efforts for migrants.

The statement confirmed that most of the rescue operations are being carried out by Libya's Coast Guard, who returned more than 7,000 people to Libya since the beginning of 2020.

According to official figures, at least 302 migrants and refugees perished on this route so far this year, but the UN indicates that the current estimated number of fatalities is likely much higher.