Polish border authorities say they have uncovered a series of underground tunnels used to move migrants from Belarus into Poland, adding a new dimension to a cross-border migration crisis that began in 2021 and has repeatedly been framed by Warsaw as a security challenge as well as a humanitarian one.
The discoveries, reported publicly in December 2025 and amplified in British and European coverage on 25 February 2026, have fed allegations that Belarus and Russia are adapting methods to bypass surveillance and fencing along one of the European Union’s most fortified frontiers.
The most detailed public account of one tunnel emerged in mid-December, when Poland’s Border Guard said more than 180 migrants had crossed into Polish territory through a passage dug near the village of Narewka in the Podlaskie region. Polish services said around 130 people were detained after the tunnel was detected and border units moved to the exit point.
According to reporting based on Polish official briefings, the Narewka tunnel ran from roughly 50 metres inside Belarus to about 10 metres inside Poland, and was around 1.5 metres high. The tunnel was discovered through monitoring systems that tracked movement patterns rather than revealing the passage itself, with Polish officials describing the detection as the result of integrated electronic surveillance along the border.
Polish officials have said the Narewka case was not isolated. Reuters reported that this was the fourth such tunnel found in 2025 in the Podlaskie region, and that two people — a Polish national and a Lithuanian national — were detained on suspicion of assisting the smuggling operation.
The broader allegation from Warsaw is that Belarus and Russia have used the movement of migrants as a tool of pressure against EU member states and NATO allies. Since 2021, Poland has accused Minsk and Moscow of encouraging or facilitating irregular migration towards the Polish border; both Belarus and Russia have previously denied orchestrating the crisis.
According to a report cited by Ynet News, Polish officials believe the tunnel discoveries may fit a broader pattern of pressure on Europe originating from Belarus and linked to Russia’s hybrid campaign against European states. The report says Polish authorities suspect some of the tunnels were planned with help from Middle Eastern specialists, while military experts cited by the Telegraph said the construction techniques resembled those associated with groups such as Hamas and Hezbollah;
Polish officials have not publicly released full technical assessments attributing the construction to specific foreign groups, but several reports noted that the engineering involved would be difficult without prior experience. Notes from Poland reported that Poland’s interior ministry said four tunnels had been discovered during 2025 and that the latest, near Narewka, had an entrance around 50 metres inside Belarus and an exit around 10 metres inside Poland, with a height of about 1.5 metres.
The tunnel cases also sit alongside longstanding reports of cross-border smuggling and attempts to distract or overwhelm border forces. Polish and regional media have regularly covered the use of contraband, including cigarettes, as well as repeated efforts by migrants to breach or cut fencing. The December incident was reported as involving electronic monitoring and a rapid response; nevertheless, officials also indicated that not all those who crossed were immediately detained.
The tunnel activity appears to form part of a broader pattern of destabilising actions linked to Belarus, including the possible use of migrant routes to move saboteurs across the border. Polish officials have increasingly presented the crisis in security terms, warning that irregular crossing routes may be exploited not only by migrants but also by hostile operatives.
The timing of heightened attention to the issue has been linked to regional diplomacy involving Ukraine, Poland and Lithuania. On 25 January 2026, Presidents Volodymyr Zelenskyy, Karol Nawrocki and Gitanas Nausėda met in Vilnius under the Lublin Triangle framework, with Lithuanian presidential communications describing discussions on security and support for Ukraine.
Poland continues to treat the Belarus border as an active security theatre. Since 2022 it has built and reinforced a steel fence and expanded electronic monitoring systems; it has also used soldiers and police to support the Border Guard during periods of increased crossings. The December tunnel case, detected through surveillance and followed by detentions, illustrates both the scale of resources deployed and the adaptability of smuggling networks and facilitators.
Image source: notesfrompoland.com
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