Members of the Clyde public were alarmed to hear explosions in the town on Sunday evening, which came following a discovery of explosive power gel on the Clutha Riverbank.

Alexandra Police confirmed the find yesterday morning, the second of its kind in recent weeks.

After further investigations following the initial find in Miners Lane several weeks ago, it was understood to be linked to the construction of the Clyde Dam 30-plus years ago.

Senior Constable Graham Perkins said members of the Explosive Ordnance Disposal team from Christchurch were called again to Clyde yesterday, to safely detonate the material.

Police have been wanting to keep the exercise low profile, and even jet boaters involved in a river sprint on Sunday had to be warned to keep clear of the site.

Because the Clutha River had lowered, the explosive material had been washed up into a crater made by the last sticks of power gel found there by a member of the public out walking their dog.

Snr Const Perkins said police had been questioned about the cost of the exercise, but confirmed it was all covered by the New Zealand Defence Force.

“The only cost to us is manpower and there were only two officers there,” he said.

It was expected there would be more explosives found in coming weeks, and advice to the public was obviously not to touch it, and report it immediately.