The victim, identified as Vimla Devi, was allegedly strangled to death yesterday. The attackers looted jewellery and valuables worth Rs 2.5 lakh from her house, they said.
The victim's son was in Orissa while her daughter-in-law was away for a meeting in Agra, police said.
An investigation team have been constituted, police said adding that efforts are on to nab the culprits.