ROME (AP) – The first three months of 2023 were the deadliest first quarter in six years for migrants crossing the central Mediterranean Sea in smugglers’ boats, the UN migration agency reported Wednesday, citing nations’ delays in initiating rescues as a contributing factor.

The International Organization for Migration documented 441 migrant deaths along the dangerous sea route between northern Africa and Europe’s southern shores during January, February and March. In 2017, 742 known deaths were documented in the same period, while 446 were recorded in the first three months of 2015.

“The persisting humanitarian crisis in the central Mediterranean is intolerable,’’ said IOM Director General Antonio Vitorino, commenting on the figures the agency released in a report.

“With more than 20,000 deaths recorded on this route since 2014, I fear that these deaths have been normalized,’’ Mr. Vitorino added. “States must respond. Delays and gaps in state-led SAR [search-and-rescue areas] are costing human lives.”

While this year has started out on a distressing note, IOM tallied higher numbers of people dead or missing in the Mediterranean in six other quarters since 2017, with the most documented in the second quarter of 2018, at 1,430.

The true number of lives lost among migrants who set out on smugglers’ unseaworthy rubber dinghies or decrepit fishing boats is unknown because the bodies of people who perish at sea often are never recovered.

Many deaths only come to light when survivors recount that their vessel set out with more passengers than the number who ultimately made it to safety.

The International Organization for Migration said it also was investigating “several reports of invisible shipwrecks”—cases in which boats are reported missing, where there are no records of survivors, remains or search-and-rescue operations. It estimated that “the fates of more than 300 people aboard these vessels remain unclear.”

Without naming nations, the agency blasted policies aimed at complicating the work of rescue boats operated in the central Mediterranean by humanitarian organizations.

The report cited a March 25 incident in which members of the Libyan Coast Guard fired shots in the air as a charity rescue boat, Ocean Viking, was responding to a report of a rubber dinghy in distress.

“State efforts to save lives must include supporting the efforts of NGO actors to provide lifesaving assistance and ending the criminalization, obstruction of those efforts” by humanitarian groups, the IOM said.

The agency’s report said the deaths of at least 127 people so far this year came in six incidents in which “delays in state-led rescues in the Central Mediterranean were a factor.” The report’s authors lamented the “complete absence of response” in a seventh situation, in which at least 73 migrants lost their lives.

The authors also cited a boat carrying some 400 migrants that remained adrift in the sea between Malta and Italy for two days before the Italian Coast Guard came to its aid.

Italy’s governments have at times impounded charity-run boats for technical reasons or, as the country’s current right-wing government is doing now, required them to disembark their rescued passengers farther away from the southernmost ports that jut out into the Mediterranean.

On Tuesday, Italy’s premier Giorgia Meloni and her Cabinet declared a six-month state of emergency to cope with the country’s latest increase in migrant arrivals.

Among the goals of her coalition, which includes the stridently anti-migrant leader of the League Party, are efforts to step repatriation of migrants who aren’t eligible for asylum. Many of the asylum-seekers who reach Italy are fleeing poverty not war or persecution and see their applications denied.

According to the Italian Interior Ministry, 31,192 migrants had arrived in Italy by sea this year as of Tuesday.

The figure didn’t include some 700 migrants crowded aboard a smugglers’ boat that apparently ran out of fuel and got towed Wednesday morning to a port in Sicily under an Italian Coast Guard escort.

Migrants aboard that vessel cheered and shouted “Beautiful Italy” when they reached Catania, Italian state TV reported.

Italy for years has sought to prod fellow European Union nations to take more of the rescued migrants who step ashore in Mediterranean countries, many with the aim of finding jobs or family members in northern Europe.

Under current EU rules, the country where asylum-seekers first arrive is responsible for them.

“The situation in the Mediterranean has been a humanitarian crisis for over a decade now,” IOM spokesperson Safa Msehli said Wednesday. “And the fact that deaths continue on its own is very alarming, but the fact that that’s increased is extremely alarming because it means that very little concrete action was taken to address the issue.”