They were both charged on Monday night with intentionally causing serious injury, recklessly causing serious injury, intentionally causing injury and recklessly causing injury. The two men, from Malvern East, have been remanded and are expected to appear before the Melbourne Magistrates Court on Tuesday morning. Assistant Commissioner Bob Hill described the attack as abhorrent and said detectives had been deployed across the state in an effort to apprehend the suspects. He said the pair had previously lived in Western Australia, the La Trobe Valley and Melbourne. Police have released images of two males after a 60-year-old man was seriously assaulted. Credit:Victoria Police

Authorised officers from Metro Trains had allegedly asked the pair, who police believed were "drunk or drug affected", to get off the Glen Waverley line service after boarding at Flinders Street Station and causing issues on the train. Shortly after getting off at Heyington station, the pair allegedly attacked Mr O'Neill before fleeing. Mr O'Neill had been leaving a private event at St Kevin's College. Earlier on Monday, Health Minister Jenny Mikakos labelled the attackers "idiots" and urged them to hand themselves in. "It is absolutely appalling that we’ve had someone who was just going about their day in an unprovoked attack, attacked and assaulted and injured," Ms Mikakos said.

"My thoughts are with Chris O’Neill and his family as he’s recovering from this senseless attack. "My message to those people who’ve committed this senseless attack on Chris O’Neill is you are idiots, you will be caught and I would encourage you to hand yourself in now." The two men police were seeking. Credit:Victoria Police Assistant Commissioner Bob Hill told radio station 3AW the pair had been allegedly acting "in a way that certainly caused concerns for others on the train". "They were vomiting and urinating in the carriage. Someone on the train alerted the authorised officers ... and they were escorted off the train.

"When they left the train they went to a gate that adjoins or leads into St Kevin's College and they were walking through the college and by chance ran into Chris O'Neill who was also there off-duty," he said. Mr O'Neill did not disclose to the two attackers that he was a member of Victoria Police, Mr Hill said, meaning the offenders would likely be charged with serious assault offences, not assault of a police officer. "I don't want to go into details, but the meeting between Chris and the two young males was by chance. He was there off-duty walking through the college grounds," said Mr Hill. "There was some sort of interaction between the two, he or may or may not have asked them to leave ... and then they have retaliated with the assault." Mr O'Neill, who has been in charge of Protective Service Officers and transit police for a number of years, was rushed to the Epworth hospital and treated for head injuries.