Latvian authorities have discovered a tunnel believed to have been used by 15 migrants to cross illegally into the country from neighboring Belarus, local media reported Tuesday.

The underground tunnel, found in the parish of Skrudaliena in the Augsdaugava municipality, was used by 15 migrants who illegally entered the country from Belarus and was discovered on Monday, Latvian Public Service Media reported, citing the State Border Guard.

Speaking to journalists, Interior Minister Janis Dombrava said that at midnight, the first tunnel in Latvia was discovered in the sector under the responsibility of the Silene Border Guard Unit.

The underground passage was found 10 meters (33 feet) from the fence in the area during a joint operation by the State Border Guard, the police, and the National Armed Forces.

According to the report, this is the first tunnel to be discovered in Latvia - a member of both the EU and NATO - as up to now migrants had attempted to enter the country by scaling the border fence.

"We will press ahead; hopefully, we will succeed in completely halting the flow of illegal migration from Belarus," said Dombrava.

Prime Minister Andris Kulbergs pressed for "full surveillance using drones 24 hours a day, seven days a week."