by Stefania Fumo

ROME, Aug. 9 (Xinhua) -- Police arrested 11 foreign nationals and seized 20 tonnes of hashish in a major international drug bust on Thursday, the Finance Guard in the Sicilian city of Palermo said in a statement.

The drug was hidden on board a Panama-flagged vessel and has a market value of up to 200 million euros (about 232 million U.S. dollars), the statement said.

Police arrested the captain and 10 crew members, all of them citizens of the Balkan country of Montenegro, on international drug trafficking charges.

The vessel left from the Canary Islands and was headed to Turkey via Egypt. Surveillance revealed that it "repeatedly turned off its Automatic Identification System (AIS) while in international waters off the North African coast in order to conceal its position and its movements," investigators said.

Hashish, made from the resin of the cannabis plant, is produced in Afghanistan, Lebanon, and Morocco, according to a 2016 report by the European Monitoring Center for Drugs and Drug Addiction (EMCDDA).

The successful operation, codenamed Operation Libeccio, was carried out in cooperation with Europol, Portugal's Maritime Analysis and Operations Center, the U.S. Drug Enforcement Administration (DEA), and Montenegro's Criminal Police Sector.

As part of a wider ongoing operation, codenamed Libeccio International, over the past four years, the Palermo division of the Finance Guard has seized over 139 tonnes of narcotics worth an estimated 1.4 billion euros.

"The Mediterranean ... is among the world basins most affected by illicit trafficking," said the Finance Guard, which is tasked with policing land and sea borders to bust smugglers, tax evaders, and other kinds of economic criminals.