death by unidentified assailants at Koldhiya Rahamganj village in Bihar's Banka district, police said.
The assailants barged into the house of Nimani Singh (70) and Chameli Devi (61) and stabbed them last night, the police said.
The motive behind the couple's murder was under investigation, they said.
A forensic team has rushed to the spot to collect samples and evidences related to the murder case, the police added.