An elderly resident at a Wagga Wagga retirement village and aged care home has suffered bleeding on the brain after he was assaulted by another resident who accused him of stealing his favourite coffee mug, according to police allegations.

Detectives have charged the 69-year-old assailant with assault occasioning actual bodily harm after the victim was left with serious facial injuries.

Local police said the incident was bizarre considering the two men had no previous history with each other.