Fire spread on board the oil tanker "Banglar Jyoti" at the Eastern Refinery Jetty on the Karnaphuli River.
The fire started at around 9:30am on Monday (30 September), said the Fire Service and Civil Defence.
According to the Control Room of the Fire Service and Civil Defence for the Chattogram region, two fire units were dispatched to tackle the blaze after the fire was reported at 11am.
However, as the severity of the flames increased, an additional six units were deployed, bringing the total to eight units currently engaged in firefighting efforts.
The cause of the fire remains undetermined at this time.
AM Majid, a local resident, said that the tanker was in the process of berthing at around 9:30am when a sudden and deafening explosion occurred.
This was followed by a rapid onset of flames, described as extremely intense and alarming.