The trio was attacked by armed assailants from a roof top in Kotwali area of the Etah city when they were going to friends' house yesterday.
They were admitted to hospital here and later referred to Medical College Agra in serious condition, police said.
Old enmity was stated to be the reason behind the attack, police said.
An FIR has been registered against Vikram, Rishi, Shiv Prasad and Jitendra, but no arrest has been made so far.