At least three people were killed and 20 others injured in a gas cylinder blast in a bus in Sadar upazila of Lakshmipur district early Monday. The deceased were identified as Suman Hossain, son of Batu Mia; Md Yusuf Mia and his brother Hridoy Hossain, sons of Sujamia. They hailed from Sadar Upazila's  Charmonsha and Banchanagar areas respectively. Among the injured were Suman Hossain, Rocky Islam, Muhammad Fahad Hossain, Siraj Mia, Hriday Islam, Shah Khan, and Abdul Malek. Ten of the injured were shifted to Dhaka Medical College Hospital for better treatment. Read: Gazipur cylinder blast: Death toll rises to 17 Witnesses said that the explosion occurred at around 2 am at Green Life Filling Station in Muktiganj area when a Ramgati-bound bus of Meghna Paribahan was refueling. The blast left three people dead on the spot and injured 20 others. Al Amin, the manager of the filling station, said the victims were mostly CNG-run autorickshaw drivers and the injured included both bus and CNG drivers. Ranajit Kumar, station officer of the Fire Service and Civil Defence (FSCD) department in Sadar upazila, said two firefighting units were sent  to the scene after receiving information. They recovered three bodies and rescued the injured. The bodies were sent to Sadar Hospital. Read more: 3 suffer burn injuries as gas cylinder blasts in Malibagh According to Kumar, the accident occurred due to the use of a substandard gas cylinder. Dr Joynal Abedin, resident medical officer of Sadar Hospital, said that the bodies were sent to morgue for autopsy while 10 injured to Dhaka for better treatment.