Coast Guard personnel detained seven people, two dredgers and two bulkhead vessels during an operation on the Kirtankhola River near Nandarchar in Barishal.
Coast Guard media officer Lieutenant Commander Sabbir Alam Sujon said the operation found sand being extracted illegally.
A mobile court, held in the presence of Barishal Sadar Assistant Commissioner (Land) and Executive Magistrate Azharul Islam, collected Tk600,000 in fines from the vessel owners.
The detainees and vessels were released after written undertakings were obtained.
Barishal Sadar Upazila Nirbahi Officer Mosammat Farida Sultana said operations would continue to protect riverside farmland and homes from erosion.
In a separate incident, Biral police said a 25-year-old woman died from burn injuries after an attack at her father’s home in Sutarpara village, Dinajpur.
Police said they detained the woman’s former husband in connection with the incident.
The victim’s grandmother alleged that the man first attempted to attack her with a knife and then set her on fire using petrol.
The officer in charge of Biral police station said the victim’s brother filed a case and the body was sent to Dinajpur Medical College for post-mortem examination.