Twenty-six people who crossed illegally from Turkey were arrested on Monday near Ahtopol, a town in Southeastern Bulgaria, police say.
A UK-plated vehicle was stopped for a police check on Monday evening. None had identity documents but claimed to be Iraqi nationals.
There were 9 men, 13 women and 4 children inside the vehicle. The driver was a Bulgarian national.
Pretrial proceedings were launched into the driver's suspected smuggling activity.
Also on Monday, police in Southwestern Bulgaria arrested 54 migrants in and near the city of Pernik, in two separate incidents. They were reported as citizens of Iraq and Afghanistan.