Police have discovered a 700-meter-long smuggling tunnel between Slovakia and Ukraine.
Slovakian Interior Minister Robert Kalinak said 13,100 cartons of cigarettes were confiscated at the entrance to the tunnel in Slovakia's Nizne Nemecke, which exits in Ukraine's Vysne Nemecke.
According to the police, the smugglers had been "unusually professional.”
The tunnel matched high mining standards and had even been fitted with a small train and tracks for transporting goods.
Both ends had been fenced off by the smugglers.
No further details were given about the suspects detained since more arrests were expected.
Officials say Slovakia had been deprived of up to 50 million euros ($62.5 million) in tobacco tax because of the tunnel.
Based on reporting by AFP, dpa, and Interfax