Miscreants set fire to a bus of Boishakhi Paribahan after pouring petrol on it in the Notun Bazaar area of Badda in the capital on Friday evening.
Police suspect that activists of a banned political organisation may have been involved in the incident.
Rashed bin Khalid, duty officer of the Fire Service, said they received information about the fire at 5:48pm on Friday. Two fire service units reached the spot at 6:20pm and brought the blaze under control.
According to locals, traffic on one side of the road was halted following the incident. It returned to normal after the fire was extinguished.