Authorities were contending with choppy waters Friday in the search for dozens of migrants believed to have drowned after their rickety boat caught fire and sank off the coast of the southern Italian island of Lampedusa.

The scope of the tragedy — with 111 bodies recovered so far and many more missing — prompted outpourings of grief and demands for a comprehensive immigration policy to deal with migrants fleeing poverty and strife in Africa and the Middle East.

Pope Francis said Friday was a "day of tears" and denounced the "savage" system that drives people to leave their homes for a better life, yet doesn't care when they die in the process.

The 66-foot (20-meter) boat was carrying migrants from Eritrea, Ghana and Somalia, the coast guard said. It started taking on water and then caught fire when someone set light to a piece of fabric to attract the attention of nearby shipping. Coast guard divers found the wreck on the sea floor, some 130 feet below the surface.

Officials say just 155 people survived of the 450 to 500 believed to have been on board.

Italian coast guard ships, fishing boats and helicopters from across the region have taken part in the search. Rescue crews hauled body bags by the dozens at Lampedusa port, lining them up under multicolored tarps on the docks.

It was one of the deadliest accidents in the perilous crossing thousands make each year, seeking a new life in the prosperous European Union. Smugglers charge thousands of dollars a head for the journey aboard overcrowded, barely seaworthy boats that lack life vests.

Hundreds of migrants reach Italy's shores every day, particularly during the summer, when seas are usually calmer. Lampedusa, 70 miles (113 kilometers) off Tunisia and closer to Africa than the Italian mainland, has been at the center of wave after wave of illegal immigration.