One of the killed was identified as Nurun Nabi, 30, from Phulbaria of Mymensingh while the other two remained unidentified.

The injured, Rabiul alias Ronny, 35, was undergoing treatment at Chittagong Medical College Hospital (CMCH), said police.

Sources said a gang of ten cattle thieves on a truck went to West Bakkhali village of Madhyam Bogachatar under Syedpur at around 2:30am.

They broke in and rounded up eight cows onto their truck from two cattle sheds owned by next-door neighbours Haji Ashraf Ali and Abdul Hamid.

The villagers rushed to the scene after Abdul Hamid heard the thieves and started screaming out for help. The villagers captured four of the thieves while the others managed to flee.

The villagers' beating was so severe that three of the thieves were killed on the spot and one injured. The mob also set their truck on fire.

Police recovered the bodies at around 5:30am and sent the injured to the upazila health complex. The injured was later transferred to CMCH.