A member of the public who saw a teenager with a knife rang 999 to report it to gardai.
The incident happened in the vicinity of Maynooth railway station on Sunday evening, May 7 last.
Gardaí responded to the call and searched the area.
In the Harbour Field area, officers noticed three youths acting suspiciously and approached them.
The gardaí found a knife on the ground and confiscated it.
The three youths were subsequently arrested.
A Garda spokesperson said: "Gardaí attended an incident on the evening of 7th of May 2023 in Maynooth, Co Kildare.
"In the course of this incident, a knife was recovered and three male youths arrested.
"All three have since been released pending referral to the Youth Diversion Programme."
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