A young man has blamed alcohol for a shocking racist tirade against a Queensland Rail security guard after it went viral online. The man was filmed by a friend verbally abusing the guard onboard a Brisbane commuter train, repeatedly calling him a "n----r", a "black c--t" and a "black dog". The five minute video was shared widely after the offender's friend posted it to Facebook, prompting widespread condemnation from other users. The incident began when the man was told the train would remain stopped until he got off, having refused to remove his feet from the seats. "Do you want to come to Australia and learn some proper English?" he is seen telling the Queensland Rail guard. "That is not the issue," the guard replies. He then tells the guard to "Learn some f---ing English 'cause this is Australia ... I can't understand you." The young male filming the encounter is heard laughing throughout the footage. After hurling abuse at the rail guard, the man begins taunting fellow passengers who protest his foul language and anti-social behaviour. He then challenges the guard to a fight, before the friend filming the incident convinces him to get off the train. Comments condemning the man flooded Facebook threads after the footage was posted and shared thousands of times. He was labelled "disgusting", "pathetic", a "disgrace", an "embarrassment", an "oxygen thief" and more explicit epithets. Around 8pm Saturday, the offender posted a status update to his Facebook page. "I was just drunk couldn't remember s--t so stop over reacting, but I am proud to be white!" it read. Around 11pm a second status update appeared on the page, expressing remorse. "I'm really sorry to everyone that was affected by the video I really can not remember anything out of all honesty the post made before was someone else I know this is no excuse," it read. "But can you all see from my point of view that I was a f----ing idiot and I'm really sorry." The offender is believed to be 17 years old. Queensland Police said on Saturday night they were aware of the video, and would investigate further with Queensland Rail officials on Sunday. Justus.