Police arrested four Tunisians, one of whom they said was a fisherman, on Saturday (August 26) after one of the migrants posted a video online showing men taking the engine of a migrants' dinghy.

Farid Ben Jha, an official in Monastir, said the dinghy, its engine and an unspecified sum of money were later seized from the men’s homes. He added that the men were charged with "criminal association with the aim of attacking people and property," the news agency AFP reported.

More lucrative than fishing

It is not the first case of piracy targeting migrants making the Mediterranean Sea journey from North Africa to Europe. Two weeks ago, prosecutors in Italy said six Tunisian "pirate fishermen" had been detained after threatening to set adrift a boat carrying 49 migrants unless those aboard handed over the boat's engine and their money.

In July, four Tunisians – a captain and three crew members – were accused of forcing migrants to hand over their phones and cash in exchange for being towed closer to Italy's Lampedusa island.

According to Italian investigators, almost half of the vessels carrying migrants that are rescued at sea are found without their engine.

The Italian news agency ANSA said investigations revealed that some Tunisians previously working as fishing crew had turned to piracy as it was more lucrative.

So far this year, around 113,000 migrants have landed in Italy, two-thirds of them from Tunisia and the rest from neighboring Libya.

Departures of sub-Saharan migrants have increased since Tunisian President Kais Said made a speech in February alleging that "hordes" of irregular migrants were causing crime and posing a demographic threat to the mainly Arab country.

A severe economic crisis and shortages of basic supplies are also said to have led to the rise in Tunisians deciding to risk the often deadly journey across the Mediterranean.

With AFP