Costa Rican police on Sunday seized 4.3 tons of cocaine originating in Colombia, the Central American nation’s second-largest drug bust ever and the biggest this year, writes Reuters.

Major cocaine busts in recent years have stoked fears that Costa Rica has become an important transit country for Colombian drugs heading toward Europe, worrying officials in one of Central America’s most stable nations.

The shipment of cocaine was transported in a container loaded with ceramic floor tiling aboard a commercial ship that arrived at the Costa Rican port of Moin from Colombia’s Caribbean port of Turbo, Costa Rica’s Security Ministry said.