The group originally consisted of 105 people who left Libya on Tuesday in a rubber boat. During the voyage across the Mediterranean, the suspects allegedly threw 12 overboard, according to Palermo police.
Passengers on the trip told police they were spared only "because they strongly opposed the drowning attempt and formed a human chain."
An Italian navy vessel caught the boat, which then moved the passengers to a Panamanian ship docked in Palermo on Wednesday where police arrested the suspects.
The twelve passengers that died were from Nigeria and Ghana.
