NSW teen critical after excavator hit

A teenage boy is fighting for his life after he was run over by an excavator on a worksite in Sydney's upper north shore.

Ambulance and police officers were called to a worksite on Koola Avenue in East Killara after 1pm on Friday where they found the 16-year-old with abdominal, chest, pelvic and lower limb injuries.

It's believed he was hit by a reversing excavator, a Safework NSW spokesperson said in a statement on Friday.

The 16-year-old is in critical condition at Royal North Shore Hospital, a spokesman told AAP.

Safework NSW is investigating the incident.