GARDAI are attempting to find out who left two pipe bombs near a halting site.
It is understood that a resident of the halting site in a Limerick city suburb discovered the pipe bombs on a small road alongside it.
Gardai were alerted and the area alongside the main Dublin road in Castletroy was sealed off while officers awaited the arrival of the Army's ordnance explosive disposal team.
The pipe bombs were made safe early yesterday.
They are said to have been viable devices.
This is the third such find this year.
On Tuesday, officers in Clare discovered a pipe bomb in a house in Tulla.
Last weekend, four pipe bombs, which were found in a derelict house in Dundalk, were made safe.