Dying people who begged for air from the crammed hold of a ship where 52 died were beaten back with knives, police said today.
Survivors have told police how smugglers used weapons to keep the migrants in the hull of the boat, where 52 people were found earlier this week.
Prosecutors in Sicily say they have detained 10 people on suspicion of smuggling and murder.
Palermo prosecutor Maurizio Scalia said the detained crew included seven Moroccans, two Syrians and a Libyan.
The bodies of the dead arrived in Palermo late on Thursday and autopsies were being performed Friday.
Revelations about the horrific treatment comes after hundreds more people are feared to have died after two more boats carrying migrants capsized off the Libyan coast.
Yesterday, in a separate incident again, a truck was found in Austria containing the bodies of 71 migrants, including several children.
The International Office of Migration has recorded 2,432 deaths linked to Mediterranean migrant crossings this year.
But it expects that figure to rise because Libyan authorities are still counting the dead from three shipwrecks off the Libyan coast in the last two days.
Scores of smugglers' boats leave lawless Libya every day, packed with migrants trying to reach the safety of Europe.