Sydney - An unattended package left on a Sydney ferry that sparked a lockdown of Australia's iconic harbourfront was revealed on Friday to be training equipment used by the transport company.The incident came just over a month after Australia was rocked by a cafe siege in central Sydney that left two hostages and a gunman dead, prompting a huge outpouring of emotion, and reflected heightened concerns about terrorist activity.Several wharves at Sydney Harbour, which was crowded with tourists and workers, were shut, an exclusion zone set up and trains and buses suspended at lunchtime on Thursday while the New South Wales Police bomb squad was called out to investigate.The package was finally declared "not suspicious" and the area reopened to the public about one-and-a-half hours later."We can now confirm that the unattended package was a training device which was not recognised as a typical training device by staff," the chief executive of Harbour City Ferries, Steffen Faurby, said in a statement."Our staff followed the correct procedure and notified police."I fully support our staff in notifying the police in the first instance."Faurby apologised to passengers for the disruption.‘Suspicious’ packagePolice would not comment on the nature of the package, but the Australian Broadcasting Corporation reported that the crew on the ferry found bottles with protruding wires and filled with nails and liquid.Interim Deputy Police Commissioner Frank Mennilli told the ABC there would be a debrief about the operation, adding that officers were not involved in security training programmes for every government department."Look, it depends, sometimes they're joint exercises, some it's about training their own people," he said."That's why we ensure that all communication, not only within the NSW police force, but all other agencies, either government or non-government is a two-way street, and we support each other in these difficult times."Separate incidentIn a separate incident on Friday, police set up an exclusion zone in a western Sydney shopping centre after an "unattended item" was discovered. It was later also found to be "non-suspicious".Australia on Tuesday raised the terrorism threat level against the police force to high for the first time, saying there were small but growing numbers of citizens involved with jihadist groups and intent on attacks.Australian Federal Police said the decision had been taken based on intelligence-gathering and discussions with partners, and was in line with the broader threat for the country, also raised to high in September, which means an attack is likely.