(UP): A man allegedly shot dead his teenage son and then killed himself over a petty dispute over consumption of milk in

in Puranpur area, police said on Tuesday.

The incident took place on Monday night when

(55) had an argument with his son

(16) after he drank some milk, they said.

Gurumukh shot his son and brother

, who tried to intervene, and later also shot himself. While Gurmukh and his son died on the spot, Avtar was rushed to the hospital, where his condition was stated to be stable, they added.

Police is probing the matter.