Sydney, Nov 13 : Ports in several Australian cities have been shut down due to a massive cyberattack, triggering concerns about shortages of key supplies amid the festive season for several days ahead. A 'serious and ongoing' cybersecurity incident hit port operator DP World Australia, which controls 18 ports in the country through terminals in Sydney, Melbourne, Brisbane and Fremantle. The port operator said late on Sunday it was in talks with rival operators to get freight moving at the ports while it worked to restore its operations, reports The Sydney Morning Herald. AMP chief economist Shane Oliver was quoted as saying that a lengthy disruption to UAE-owned DP World's operations 'could ripple through the broader economy and help trigger another interest rate rise'. 'It goes to the nature of the supply shock here, and this could have an impact on the prices, and inflation rate, of goods, which has been coming down. If this stops that, or it pushes up prices, then the Reserve Bank could be looking at it at their December meeting,' he was quoted as saying. Major Australian ports are expected to remain closed, following a "cyber security incident". However, online shoppers are likely to escape the worst as most of them use air freight for delivery. The Australian Federal Police confirmed it was investigating the incident, which cyber experts believe to be a ransomware attack. Home Affairs and Cybersecurity Minister Clare O'Neil described the hack as serious and ongoing. 'This incident is a reminder of the serious risk that cyberattacks pose to our country, and to vital infrastructure we all rely on,' she said. According to cybersecurity researcher Troy Hunt, disruptions to Australian consumers could last weeks and affect Christmas deliveries. /IANS