A marketing stunt has turned into an HR nightmare with over twenty people injured at the launch of a mobile phone.

At least twenty attendees were squashed, barged, trampled and possibly stabbed at an event promoting LG’s new G2 phone in South Korea. The company had promised to hand out 100 free phones at the event, leading to a mass turn-out. The phones were to be awarded based on vouchers hidden in helium balloons, all the crowd had to do was catch one to win.

It probably sounded like an excellent idea in marketing meetings beforehand, but when a large crowd armed with pellet guns, a large spear and other tools for popping balloons arrived, the phone company may have already begun to tally the medical bills.

As the crowd surged to capture the rapidly-escaping balloons many were injured by the mass of bodies and light weaponry used in the clamour for free phones. It is unclear whether the spear one woman had brought caused any injuries. LG South Korea has agreed to pay medical expenses, according to some reports.

A video report from a local news agency is available online.