The suspected killer was identified as Rabiul Islam, 26, a listed criminal, son of Tara Mia while the van puller was identified as Suruj Mia, 45, son of Kashem Ali of Jagodal Dangapara in the upazila.
Shakila Parveen, officer-in-charge of Birganj Police Station, said Rabiul Islam swooped on Suruj Mia and two others, including his three-year-old son Ekramul, and stabbed them indiscriminately over previous enmity, leaving Suruj dead on the spot and two others injured.
The incident took place while the trio was returning home after offering Fazr prayers at a local mosque.
However, local people managed to catch Rabiul after a hot chase from Tero Mile in Kaharole upazila and brought him back to the murder spot around 8 am.
Later, they gave Rabiul a good thrashing and set him on fire, leaving him dead, said the OC quoting witnesses.
On information, police went to the spot and brought the situation under control.