A hospital nurse has been injured by a stray bullet as a townhouse was shot at in western Sydney in a suspected crime-gang related attack.

Police said the nurse suffered a minor injury to her leg after the bullet went through a window at the rear of Auburn Hospital on Monday night.

Police were called to a townhouse complex on Auburn Road shortly before 8pm and found bullet holes in the front of the building.

Residents inside at the time were not injured.

Police were told at least two men, dressed in black, were seen getting out of a vehicle near the driveway of the townhouse and firing a number of rounds.