A number of Tunisian fishermen are preying on migrant boats, stealing their engines as well as the migrants’ money and mobile phones, Italian prosecutors say.

Several Tunisian fishermen have effectively become pirates, robbing boats carrying sub-Saharan Africans to the coast of Sicily.

The fishermen reportedly steal the engines of the boats as well as migrants’ money and mobile phones, Italian prosecutors in the Sicilian city of Agrigento said on Sunday (July 30).

If passengers of the migrant boats resist, the prosecutors report, the fishermen-turned-pirates threaten them with knives and block their boat until they get what they want.

The prosecutors in Agrigento say they have worked on several such cases over the past few weeks.

Four people from North Africa aged between 43 and 50 have been detained, investigators said.

They reportedly are the captain and crew of Tunisian trawler Assyl Salah and were arrested last week by the Agrigento flying police squad, finance police and coast guard from Lampedusa on suspicion of stealing from migrants in the Mediterranean.

A preliminary investigations judge confirmed the arrest orders, ruling that the suspects must be held in pre-trial detention.

The alleged crime of piracy on the high seas breaks the United Nation’s ‘Convention on the Law of the Sea’ and the Italian shipping code. People who violate it face up to 20 years in prison.

According to investigative sources in Agrigento, almost half of the vessels carrying migrants that are rescued at sea are found without their engine.

Tunisian gangs aboard fishing trawlers steal the engines and then sell them to migrant traffickers, they said.