Police are hunting a person who placed violent booby traps along a running trail north of Sydney.

A runner was in the Lake Macquarie State Conservation Park at Bolton Point, south-west of Newcastle, on Monday morning when he noticed a suspicious pile of leaves in the middle of the track.

Hidden amongst the leaves were a pile of wine corks with nails protruding from them.

The weapons are similar to ‘caltrops’, used by the Romans and Ancient Greeks in war, and are designed to pierce a person or animal’s foot.

The runner who discovered the booby trap continued along the trail and found two more piles of leaves, hiding more spikes.

Police were called and are now investigating the incident, releasing images of the gruesome weapons.

Anyone with information is urged to call Crime Stoppers on 1800 333 000