Two people - both brothers - were shot dead on Monday in Uttar Pradesh's Baghpat district, police said.
The incident took place in Bawli village when over a dozen armed men reached the house of the deceased and opened indiscriminate fire.
Raj Kumar (28) and Jayveer (25) were killed on the spot, a police officer told IANS.
Their neighbour Brahm Singh, who tried to come to their rescue, was critically injured and has been rushed to a nearby medical facility.
The officer said in 2010, Raj Kumar and Jayveer had killed a member of the Ajit alias Happu gang.
Monday's killings were apparently carried out in revenge by the gang members.
Extra security personnel have been posted in the village as there is anger in the village over the killings, a home department official said.