The injured were identified as Asadur Rahman, 30, son of Abdullah from the village, his mother Sonawara Khatun, 55, Sohag Uddin, 25, son of Farid Uddin, Mizanur Rahman, 22, son of Fazlul Haque and Nazrul Islam, 30, son of Abu Kalam.
Police and locals said Asadur was preparing to inflate balloons on his yard. They said Asadur created hydrogen gas by mixing caustic soda and aluminium powder with water and was inflating toy shaped balloons when the gas cylinder exploded injuring five people.
Seven goats were killed and a number of furniture was damaged.
Dr Sadia Sultana of Dhunot Health Complex said they sustained almost 50 percent burns. The injured were shifted to Shaheed Ziaur Rahman Hospital.
Ismail Hossain, officer-in-charge of Dhunot Police Station, said the accident occurred for using hydrogen instead of helium to inflate balloons.