Latvia said on Tuesday a tunnel had been discovered under the border with Belarus and announced plans to combat networks that it says are helping a growing number of migrants cross the frontier illegally.
Latvian soldiers last month used teargas and fired a warning shot to stop migrants trying to enter from Belarus, which shares a 173-km (107-mile) border with European Union member state Latvia.
"The protection of Latvia's eastern border will be strengthened, with closer cooperation between the Border Guard, State Police, National Armed Forces and security services, and more intensive use of drones for early detection and detention of illegal migrants," Interior Minister Janis Dombrava told a joint press conference with Prime Minister Andris Kulbergs.
European nations have expressed concern over unregulated migration in recent weeks following an inflow of tens of thousands of people from Morocco to the Spanish exclave of Ceuta, although most of those migrants have since left.
Kulbergs said criminal networks were facilitating the migration from Belarus into Latvia, bringing them inside Europe's borderless Schengen area, but that the final destination for migrants was elsewhere on the continent.
"They migrate to where it's easier (to enter the EU). So we must not be the easiest place," Kulbergs told the press conference.
He pledged to target networks transporting the migrants from the border to their destinations, as well as any support points for migrants in Latvia, as part of what he called "Operation Werewolf".
"If everything goes according to plan, we are confident that we will already deal a serious enough blow to the system," Kulbergs said. "I want to tell the organisers: everything will be put to an end."
Kulbergs told Reuters last month the migrant situation was a "hybrid threat" that had caused Latvia to double the number of guards at the border.
Latvia will cooperate with neighbours Estonia, Lithuania, Poland and others to stop the flow of migrants, the government said in a statement.
Lithuania said in July it had also found a tunnel that migrants were using to enter from Belarus.
