Demand for self-defense items such as pepper spray, batons and whistles have spiked in the wake of a recent spate of indiscriminate attacks in South Korea.

Online transactions for self-defense equipment shot up 399 percent for the period of July 21 to Aug. 3, from a month earlier, according to Interpark Commerce. Items for sale on the e-commerce platform include expandable batons, pepper spray and brass knuckles.

The surge occurred shortly after a stabbing rampage near Seoul's Sillim Station and a similar attack near Seohyeon Station in Seongnam, Gyeonggi Province.

Under the Act on the Safety Management of Guns, Swords and Explosives, the possession of firearms, swords, explosives, gas sprayers, electronic stun guns and crossbows is generally prohibited for ordinary citizens. Only manufacturers, dealers, or those permitted by law to carry them for their official duties, such as authorized security personnel, may possess them.

Otherwise, people must obtain permission from the police, and most permits require people to go through a rigorous qualification process.

Expandable batons are not covered under the law, but specific ones distributed to police are prohibited for use by ordinary citizens. Pepper sprays and whistles can be carried without permission.

Police have cautioned buyers to be aware of the laws on possessing self-defense items.

“When selling self-defense products that require police permission, dealers should notify buyers of the obligations of getting permission," a police official was quoted as saying in a local media report Sunday.

The official added that those who receive the items as gifts or were not notified of the reporting requirements should contact their local police station for guidance.