At least 29 migrants have died from hypothermia while traveling from North Africa to Italy aboard a smuggler's life raft in heavy seas, the Italian Coast Guard said Monday.

The victims were among more than 100 people packed aboard an inflatable life raft who were trying to cross the Mediterranean in rough seas and freezing temperatures, said Italian Coast Guard commander Filippo Marini. The migrants had summoned help via satellite telephone while they were 100 miles off the coast of the southern Italian island of Lampedusa.

Marini said a merchant ship in the area responded until the coast guard arrived and took on board both the survivors and the victims in seas with waves as high as 30 feet.

Since the beginning of 2014, more than 150,000 migrants have arrived in Italy on unseaworthy boats, many refugees of war and conflict. Hundreds die each year trying to make the crossing, including 360 migrants who died off Lampedusa in November 2013.

The desperation of migrants seeking a better life in Europe has fueled a boom in human trafficking. Around New Year's, Italian authorities found and seized two cargo boats full of mostly Syrian migrants that were programmed to sail straight into the Italian coast after smugglers had abandoned the helm.