Three people, including a child, were injured in the incident
An 11-member team of the Anti-Terrorism Unit from Dhaka has visited the blast spot at No 2 Gate under Panchlaish police station in Chittagong.
Members of CID, Chittagong Metropolitan Police (CMP) Bomb Disposal Unit, and Police Bureau of Investigation (PBI) have collected evidence from the spot and are working to ascertain the cause of the blast.
After visiting the spot on Friday night, CMP Additional Commissioner Amena Begum told the media that they were not ruling out the possibility of sabotage behind the blast.
"The blast occurred around 8:30pm when two policemen were on duty. All of a sudden, the policemen heard a bang following a spark," said Amena.
"Right now we cannot say anything for sure. No splinter was found at the spot."
She added: "We are suspecting the blast to be an act of sabotage. The members of the Power Development Board are also working to find out the cause of the blast."
CMP is also on high alert, she furthered.
Currently, three people, including a policeman and a minor are undergoing treatment at Chittagong Medical College Hospital (CMCH).
The injured police members are: Traffic Sergeant Arafat Hossin Bhuyian, Assistant Sub Inspector Md. Atauddin.
The traffic sergeant was critically injured with 8% burn injury in his body, said the on-duty doctors at the CMCH.