Gardai in Limerick found the explosive devices in a laneway in the Castletroy area last night around 10pm.
The army's ordnance explosive disposal team were contacted and made the pipe bombs safe after midnight.
On Tuesday, officers in Clare discovered a pipe bomb in a house in Tulla. The discovery was made after a 22-year-old man and a 17-year-old boy were stopped by gardai and shotgun cartridges and drugs paraphernalia were found.
One theory that officers are investigating is whether the 22-year-old had recently begun to manufacture pipe bombs.