Knuckle-dusters and stun guns were among a haul of weaponry seized by officials at Belfast International Airport within the last two weeks.
Border Force officers said they also uncovered CS gas sprays, extendable steel batons, butterfly knives and two illegal air rifles.
The majority of the offensive weapons were found in luggage offloaded from holiday flights returning from Bulgaria, Turkey and Croatia.
Members of the public have been warned that if they smuggle such weaponry they face penalties including the risk of imprisonment.
John Spence from Border Force in Northern Ireland said: "My message to holidaymakers is simple - don't do it.
"We know which flights are being used to bring weapons into the UK and, as these recent seizures show, we're very effective at finding them.
"At best, you'll have the weapons taken off you and at worst you'll face a criminal conviction.
"Border Force is here to ensure these weapons are kept out of the UK as they can serve no purpose other than to harm people."
He added: "We don't want these deadly items on our streets."