The victims were identified as Mohammad Ali, 70, and his wife Ranwara Begum, 60, residents of the Bashkuri Karbala School area under Bailor Union.
Accused Riyad Hasan Raju, 30, has been detained in connection with the gruesome incident, said Additional Superintendent of Police (Crime and Operations) Md Abdullah Al Mamun.
Police said that last Wednesday, Raju strangled his mother Ranwara Begum during the day and hid her body inside the house. Later that evening, when his father returned home, Raju killed him by striking him with an axe. He then buried both bodies inside the house.
In an attempt to mislead others, Raju later informed his sisters that their parents were missing. However, his sister Zarina Khatun became suspicious upon visiting the house and noticing fresh soil and bloodstains on the floor.
She informed neighbors who caught Raju and subsequently informed the police.
Law enforcement officers arrived at the scene, recovered the buried bodies, and took Raju into custody, reports UNB.
Md Mansur Ahmed, officer-in-charge of Trishal Police Station, said Raju confessed during preliminary interrogation.
He said he had been unemployed and had asked his parents for money to start a business. After they refused, he killed them out of anger.
The OC said the bodies have been sent to Mymensingh Medical College Hospital for autopsy.