Emergency services were called to Grawin Opal Fields, about 72 kilometres north-west of Walgett, just after midnight following reports a fight had broke out between two men.

Officers were told the men were known to each other, and a physical altercation had broken out.

A 57-year-old man was treated at the scene for stab wounds to his abdomen and serious facial injuries.

He was taken to Walgett Hospital before being airlifted by the Westpac Rescue Helicopter Service to the Tamworth hospital.

A 36-year-old man was taken to Lightning Ridge Hospital for treatment for a serious injury to his hand.

Officers attached to the Central North Police District have launched an investigation into the circumstances surrounding the incident.