The ministry said in an August 19 statement that Belarusian authorities detained the three on August 18, a day before a meeting of the Union of Poles in Belarus (SPB).
Last year, Minsk accused the SPB of fomenting a revolution among Belarusian Poles.
Warsaw intervened in the dispute. Relations between Warsaw and Minsk soured when Belarusian President Alyaksandr Lukashenka accused Poland of interfering in Belarus's internal affairs.
The dispute led to a series of tit-for-tat expulsions of diplomats from both countries.
Belarus And Poland
An anti-Lukashenka demonstration in Warsaw on February 22 (RFE/RL)
LOOKING OVER THE FENCE: In the 12 months leading up to today's presidential elections, Polish citizens have taken a strong interest in the fate of their neighbors, the Belarusians. Some say this is because the two countries are geographically linked and it is in Poland's best interest to be surrounded by democratic friends. Others say it is because of Poland's own strong history fighting against oppression. Regardless of the reason, one thing is indisputable: Poland is almost as invested in the results of the March 19 election as Belarus is....(more)
MEET THE CANDIDATES: Read brief biographies of the four candidates in the March 19 election.