Airlines started flying a backlog of thousands of stranded passengers to and from Australia\'s second-largest city today after an ash cloud from a Chilean volcano began to clear. Most flights between Australia and New Zealand, however, remained grounded due to the drifting cloud of fine grit, which can damage aircraft engines. Several flights to and from the south-eastern city of Melbourne, the island state of Tasmania and New Zealand were cancelled yesterday after the ash moved across the Pacific from Chile, where it has been spewing from the Cordon Caulle volcano since June 4. In total, more than 55,000 passengers have been stranded by the disruptions, which came amid a three-day holiday weekend in Australia. After the cloud moved away from Melbourne today, national carrier Qantas and its budget subsidiary Jetstar resumed flights into and out of the city. Melbourne-based Tiger Airways became the last airline to resume Melbourne operations, company spokeswoman Vanessa Regan said. Qantas estimated it could take 24 to 48 hours to clear just the Melbourne backlog. Both Qantas and Jetstar continued to ground flights from the Australian mainland to Tasmania and New Zealand, citing the danger ash poses to engines. The Australian air force ignored the danger to fly stranded Tasmanian politicians to the national capital, Canberra, in a jet to attend parliamentary sittings, the government said in a statement. The government holds a single seat majority in the House of Representatives so any absences could bring it down. Virgin Australia cancelled flights yesterday but started flying out of Melbourne, Tasmania and New Zealand again early today with a reduced schedule, flying below the cloud. National carrier Air New Zealand never suspended services, instead choosing to divert flights and alter altitudes. Qantas rejected flying below the cloud. \"This is about Qantas safety standards and procedures in place. We want to assure the safety of crew, the safety of our passengers and ultimately the safety of our airlines,\" said Qantas spokeswoman Olivia Wirth. \"So until such time that we get greater clarity on the ash cloud and until it removes, we will not operate services.\" New Zealand\'s Civil Aviation Authority had some good news for airlines flying below the cloud. It said it was now safe for planes to fly up to 27,000ft (8,000m), up from 20,000ft (6,000m). The plume of ash could disrupt travel for the next few days, according to Airservices Australia. Flights in the South American countries of Chile, Argentina, Uruguay and Brazil were grounded for some days following the eruption. The flight warnings and disruptions come 14 months after air traffic was grounded across Europe after the eruption of Iceland\'s Eyjafjallajokull volcano.