The electronics manufacturer was holding a promotinal event for its new G2 smartphone in Seoul, offering up to 100 people the chance to win one of the smartphones for free.
The Korea Times is reporting LG released balloons in the air with free G2 coupons attached, granting a free phone to anyone who got their hands on a winning voucher.
What LG wasn't counting on, however, was attendees coming armed with BB guns and other weapons.
Reports are suggesting that after LG released the balloons mayhem ensued, leaving up to 20 people injured, some requiring hospitalisation.
"Some were using BB guns to shoot the balloons," one blogger wrote according to the Korea Times.
LG reportedly acknowledged that it was responsible for a lack of crowd control, cancelling all future outdoor G2 promotional events across South Korea.
The company has also reportedly promised to cover any medical costs incurred by attendees.
"We will provide them with proper medical treatment as we are responsible for the event," the company said, according to the report.