A ministry spokeswoman said 38 men, 33 women and 58 children were found hidden behind bottles of sparkling water at the border crossing of Kapitan-Andreevo, adding that their state of health was not a cause for concern.
The migrants' attempt to flee their homeland recalled a case with a more tragic outcome in August when 71 migrants were found to have frozen to death in a refrigerated lorry designed to carry frozen food after traffickers abandoned the vehicle in Austria.
The country has to date avoided the mass influx seen by neighbouring Greece, which thousands of refugees have sought to reach in perilous crossings by sea.
But Bulgarian authorities nonetheless fear increased arrivals ahead of the winter, leading police today to make checks of some 6,000 vehicles and arrest 16 suspected traffickers as well as 495 migrants nationwide.