LONDON

Thirty-seven suspects were arrested across Europe in a joint operation against "a highly violent criminal cell from the Western Balkans," Europol said Thursday.

"Led by a national of Bosnia and Herzegovina, this powerful criminal cell was mainly involved in the large-scale trafficking of drugs and firearms across Europe," the EU's law enforcement agency said in a statement.

The arrests, including of the cell's ringleader, were carried out simultaneously across Croatia, Slovenia, Bosnia and Herzegovina, the Netherlands, Italy, Belgium and Germany.

Security forces have seized €148,000 (over $158,000), 18 firearms, including two machine guns, and 2,512 pieces of ammunition as well as 500 grams of TNT with remote detonators.

During the search, over 15 kilos of cocaine, 11 kilos of heroin, three kilos of amphetamine, seven kilos of marijuana, 10 kilos of hashish, law enforcement uniforms and fake ID documents were seized, said Europol.

Along with the Europol unit, various security force units from Austria, Belgium, Bosnia and Herzegovina, Croatia, Germany, the Netherlands, Slovenia and the US took part in the operation.