A lighter ship carrying 2,200 tonnes of scrap sank in Karnaphuli River early Wednesday.
"The ship was anchored near Sadarghat area after loading scrap from the outer anchorage of Chattogram Port for its next voyage to Dhaka. But it sank at around 1:30am after a clash with a buoy. The high tide at that time tore the anchor rode of the ship and then the vessel clashed with the buoy," said Belayet Hossain, proprietor of Nippon Shipping Trading.
The ship named MV Barnia Prince-2 was owned by Abul Khair Group, he added.
Two private companies -- Genuine Enterprise and Air Enterprise -- have been working to rescue the ship since morning.
Proprietor of Air Enterprise told The Business Standard, "We reached the spot at around 10:00 am. Our team has started the rescue operation."