Four viable pipe bomb devices have been made safe by Army bomb disposal experts. The explosives were discovered on waste ground off the Malahide Road in north Dublin as part of investigations in the area.
The Defence Forces bomb squad was called out and spent an hour making the devices safe before removing them for further examination.
No controlled explosions were carried out.
A spokesman said the remains of the devices will be handed over to gardai for their investigations.
Provisional figures showed the Army bomb squad were called out more than 200 times last year to deal with suspected explosives and dangerous substance and dealt with 96 viable pipe bomb type devices.
An area near a travellers' halting site off the Malahide Road was raided in October as part of investigations into a pipe bomb maker supplying explosives to gangs.