Supaul: Four labourers were asphyxiated at Simaria village under Triveniganj police station area in the district today.
Police said here that the labourers were constructing a septic tank at a house when they fell unconscious.
Sources said that all labourers were admitted to a local hospital where they died during treatment.
The deceased were identified as Umesh Mandal, Upendra Mandal, Rajesh Mandal and Santosh Mandal.
The bodies had been sent for autopsy.