The incident happened at Lachhu Tola in Nayagaon village under Shyampur Bhatha police station in the district, and the deceased as well as injured belonged to a family of migrant labourers.
Shyampur Bhatha Station House Officer (SHO) Anil Kumar Prasad said, "The family had left open the knob of gas regulator after switching off the stove last night. It seems rats cut the gas pipe, or it cracked somehow. The gas leaked and spread in and around the kitchen."
The SHO said that one woman died inside the house itself, while the other succumbed to her burn injuries while being taken to Sri Krishna Medical College and Hospital (SKMCH) in Muzaffarpur. Four other injured have been admitted there.
The dead bodies have been sent for postmortem, while the police is probing the matter to find out whether there was any foul play in the incident.