In separate incidents, three workers were killed while extracting stones from three quarries at Gowainghat and Companiganj upazilas in Sylhet on Tuesday.
Police and witnesses said the tragic incidents took place in Jaflong and Shah Arpin areas in the afternoon and evening, respectively.
The deceased were identified as Nazim Uddin, 19, Usman Mia, 28, and Ekhlas Mia, 30.
Witnesses said Nazim had died on the spot after the pipe of a dredger machine, locally known as Boma Machine, caved in while collecting stones from a quarry at Jaflong around 4:30pm.
Confirming the incident, Gowainghat police station OC Delwar Hossain said several other workers were also injured. One of them, Bahar Mia, was admitted to a local hospital in critical condition.
Around 7pm, Usman died in a mudslide after falling into another quarry at Jaflong - near the one where Nazim died.
Delwar said police later recovered both bodies and sent them to Sylhet MAG Osmani Medical College Hospital for autopsies.
Raids were on to detain the owners of the quarries and people concerned, he said.
Meanwhile, Ekhlas died while loading stones in a vehicle at Shah Arpin, said Companiganj police station OC Shafiqur Rahman Khan.
His body was recovered and sent to MAG Osmani Medical College Hospital too for autopsy.