A launch named MV Zahid-8 was hijacked while docked on the banks of the Buriganga River in the Hasnabad area of Sadarghat, Dhaka.
Following the incident, launch manager Shah Alam filed a written complaint with the South Keraniganj police station.
Both the police and the complainant confirmed the incident on Thursday.
According to the complaint, on Tuesday, around 5pm, the MV Zahid-8 was moored at Ripon Dockyard in Hasnabad.
The accused, Minju Dhali, along with his three sons — Roni, Soni, and Babu — along with several unidentified individuals, boarded the vessel.
They initially sought Ashraful Alam Zahid, the owner of the company, demanding extortion money.
When they failed to locate the owner, they armed themselves with makeshift weapons and assaulted the launch staff on Wednesday, around 4pm, in an illegal mob attack.
The group then forcefully launched the MV Zahid-8, taking it to an area in front of Pargendaria Iqbal Chayaman Dockyard in South Keraniganj.
The complaint further details that the attackers assaulted and seriously injured several employees, including drivers Babul and Mizan, and crew member Jamal Shukanid.
They also demanded a large sum of money as extortion, threatening to dismantle and sell parts of the launch if the payment wasn’t made.
Shah Alam, the manager of MV Zahid-8, said: "Our launch has been hijacked. I have filed a written complaint with Kotwali police."
Sub-inspector Zulfikar from South Keraniganj police station confirmed the filing of the complaint and said that the incident is under investigation.