A man allegedly killed his 39-year-old cousin with a sword following an argument over using a water pump at a common well in Kotwali area of Nagpur on Wednesday, police said.

The deceased was identified as Abhishek Shahu. His 70-year-old father Hariom, mother Sarla (66) and his younger brother Sagar (35) were also injured by the accused in the sword attack, they said.