Around 8:30pm, the gang of robbers tried to force their way into Aparupa Jewellers and Guinea Gold Jewellers in the DM market opposite the GPO building, CMP ADC (South) Mizanur Rahman said.
But he was not sure whether the robbers could decamp with some jewellery -- and if so, how much.
At least 13 people were injured in the violence as panic spread when the robbers lobbed handmade bombs and fired at random.
The injured have been admitted to Chittagong Medical College and Hospital (CMCH).
However, one of them died undergoing treatment around midnight, said Kotwali Police Station OC Mohiuddin Selim.
He said the microbus used by the robbers in the attempted heist was later recovered around 9:45pm from near the Newaz Hotel at East Madarbari in the port city.
Bags, masks and dresses have been found in the microbus.