Police are searching for a teenage boy caught with a bow and arrow at his high school near Coffs Harbour in northern New South Wales.

The NSW Education Department has confirmed the incident at Woolgoolga High School, north of Coffs Harbour, just before 9:00am (ADST).

Police say the 16-year-old had the bow and arrows with him on the school bus.

They say the boy told other students he planned to use the weapon to damage a teacher's car.

Students alerted staff at the school, where a teacher confronted the teenager in the school grounds and wrenched the weapon from him.

Police were called but the boy ran from the school before they arrived.

A police dog tracked his scent for about three kilometres to the Pacific Highway but then lost it.

The search is ongoing.

A spokesman for the Education Department says the school is remaining open as normal after the incident.