The traders were returning to their neighbourhood after buying vegetables from the wholesale market in Manikganj’s Jaagir.
The incident occurred in front of the Sadar Upazila administration offices around 11:30am on Sunday, said Sadar Model Police Station OC Nasir Uddin.
The dead have been identified as Sohan, 21 and Shamim, 23.
The two were among some people who gathered around a straw fire to ward off the cold, OC Nasir told bdnews24.com.
Sohan’s aunt insulted Shamim because of the way he was stoking the fire and an argument broke out that eventually developed into a fight, he said.
Sohan and Shamim stabbed each other and both died on the scene, the OC said.