At least 2,000 birds captured by some poachers were released from a trap in the Padma Char area of Munshiganj on Wednesday.
A video clip that went viral on social media showed the former general secretary of Jubo League's Rarikhal union unit, Md Saikat Khan, freeing the birds.
Saikat said he and his friends heard the chirping of birds when they went to visit the area on Monday afternoon and discovered that hundreds of birds remained trapped inside a hut there.
They also tried to catch three poachers there but the trio managed to flee.
The poachers trapped different types of Munia birds with nets when the latter came to eat in paddy fields of Padmar Char, Saikat said, adding, "We also found a few nets in the adjacent field and destroyed them with fire."