Two of the deceased were identified as Zahirul, 35, and Mofazul, 30, of Sonargaon upazila of the district.

Anisur Rahman, officer-in-charge of Araihazar Police Station, said local people challenged the trio early Thursday seeing their suspicious movement in the area. 

As they tried to flee the scene, the locals caught them and gave them a good thrashing, leaving them dead on the spot.

Later, police recovered the bodies and sent those to Narayanganj General Hospital.