A drive-by shooting outside a nightclub in the Australian city of Melbourne inflicted "horrific injuries" that killed a security guard and wounded three men, police said Sunday, but there was no suggestion yet that the attack was terrorism-related.

Australia has some of the world's toughest gun control laws, adopted after its worst mass murder, when a gunman killed 35 people at Port Arthur in the island state of Tasmania in 1996.

Sunday's shooting took place around 3.20 a.m. in the lively entertainment district of Melbourne's southeastern suburb of Prahran, police said.