Police issue immediate warning as 11 explosive devices discovered in Australian capital

Authorities issued a public warning on Wednesday after the chilling discoveries - in open areas surrounding Lake Ginninderra.

ACT Policing said it is treating the situation with utmost seriousness as investigations continue.

But for now, the force indicated there was no evidence suggesting similar devices had appeared in other areas of Canberra.

Detective Acting Inspector Anna Wronski from ACT Policing spoke to ABC Radio Canberra about the threat.

"Any explosive is dangerous, thankfully there haven't been any reported injuries but we are concerned these devices have been left in public where anyone could step on them and pick them up," she said.

"We are treating this very seriously and investigations are ongoing."

She urged residents to avoid handling any suspicious objects they encounter.

"What we're actually asking the community to do, is if they come across any of these suspicious items, to immediately call police on triple 0," she said.

Police released photographs showing the devices as silver, pipe-shaped objects on the ground.

The devices were scattered between the capital's Joynton Smith Drive and Ginninderra Drive in the Belconnen district.

They feature screw tops and are small enough to be held in one hand.

Authorities confirmed no injuries have yet been reported in connection with the discoveries.

After the police warning, the US embassy in Canberra urged Americans to be on their guard.

US citizens were given a three-point warning to exercise caution in the area, call police if they see anything suspicious, and monitor local media for updates.