An Italian court ruled Tuesday that the captain of a migrant boat that sank in 2015, killing up to 900 people, was responsible for the Mediterranean's worst disaster since World War II.

Judges in Catania ordered Mohammed Ali Malek, a Tunisian national, to serve 18 years for multiple manslaughter, human trafficking and causing the tragedy. Syrian Mahmoud Bikhit, accused of being his first mate, was handed a five-year sentence.