A ship carrying African migrants to Europe caught fire and capsized off the Italian island of Lampedusa on Thursday, killing at least 114 people as it spilled hundreds of passengers into the sea, many of whom drowned from not knowing how to swim, officials said.
Over 150 people were rescued but about the same number are still unaccounted for.
The death toll in the accident passed 100 after rescue divers found at least 20 bodies near the sunken ship, an Italian coast guard official told Reuters. Earlier, officials said 94 were dead.
Cmdr. Floriana Segreto said the coast guard found the boat on the sea floor at a depth of 130 feet, according to the Associated Press.
She added that they are waiting for the weather to improve Thursday and will then divers start recovering more bodies. They have yet to go inside the boat.
It was one of the deadliest accidents in the notoriously perilous Mediterranean Sea crossing from Africa for migrants seeking a new life in the European Union.
"It's an immense tragedy," said Lampedusa Mayor Giusi Nicolini.
"We need only caskets, certainly not ambulances," Pietro Bartolo, chief of health services on the island, told Radio 24. He gave the death toll of 94 but told Sky TG24 he expected that to rise as search operations continued.
Antonio Candela, the government's health commissioner for Palermo, said 159 people had been rescued.
Only three of the estimated 100 women on the ship have been rescued and no children have been saved so far, Simona Moscarelli, a legal expert for the International Organization for Migration in Rome, told The Associated Press.
"Most of (the migrants) can't swim. Only the strongest survived," she said, basing her comments on her group's early interviews with survivors.
Lampedusa is closer to Africa than the Italian mainland -- a mere 70 miles off the coast of Tunisia -- and is the frequent destination for smugglers' boats. Blue, white, green and black tarps covered the bodies at the port.
Coast guard ships, local fishing boats and helicopters from across the region were combing the waters trying to find survivors, said coast guard spokesman Marco Di Milla. The boat left from Tripoli with migrants from Eritrea, Ghana and Somalia, he said.
Italy's interior minister, Angelino Alfano, told reporters that 66-foot boat began taking on water after its motor went out. The passengers didn't have any cellphones to call for help so instead set a small fire to flag passing ships.
But because gas had mixed with the water flooding the ship, the fire then spread to the ship itself. Passengers fled to one side of the boat, flipping the ship, and some 450-500 people were flung into the sea, Alfano said.
Pope Francis, who visited Lampedusa in July, quickly sent his condolences .
It was the second shipwreck this week off Italy: On Monday, 13 men drowned while trying to reach southern Sicily when their ship ran aground just a few yards from shore.
Hundreds of migrants reach Italy's shores every day, particularly during the summer when seas are usually calmer. They are processed in centers, screened for asylum and often sent back home. Those who aren't usually melt into the general public and make their way to northern Europe, where immigrant communities are bigger and better organized. In Italy, migrants can only work legally if they have a work permit and contract before they arrive.
According to the U.N. refugee agency, 8,400 migrants landed in Italy and Malta in the first six months of the year, almost double the 4,500 who arrived during the first half of 2012.
It's still a far cry from the tens of thousands who flooded to Italy, especially through Lampedusa, during the Arab Spring exodus of 2011.
The numbers, though, have spiked in recent weeks, particularly with Syrian arrivals.
The U.N. High Commissioner for Refugees recorded 40 deaths in the first half of 2013 for migrants arriving in Italy and Malta, and a total of 500 for all of 2012, based on interviews with survivors. Fortress Europe, an Italian observatory that tracks migrant deaths, says about 6,450 people died in the Canal of Sicily between 1994 and 2012.
The Associated Press contributed to this report.