The impact on Australia’s transport industry from an ash cloud created by a Chilean volcano intensified Tuesday with Qantas Airways Ltd.Cancelling flights to and from the Pacific nation’s largest city of Sydney.Qantas said it’s possible that flights to Australia’s second-largest city Melbourne could also be affected. It and rival carrier Virgin Australia Ltd. (VBA.AU) also cancelled Adelaide and Canberra flights.

This is going to unfortunately have a knock-on effect for many travelers looking to travel today,” Olivia Wirth, a spokeswoman for Qantas, told ABC radio.Travel plans in Australia and New Zealand were thrown into chaos for six days last week when an ash plume from Chile’s Puyehue-Cordon Caulle volcano complex drifted east across the Atlantic and Indian Oceans.The latest disruptions are a blow to an airline industry already suffering from higher jet fuel costs and the impact on travel from floods in Queensland state and Japan’s devastating earthquake and tsunami in March.

Wirth said it’s unclear when Qantas will be able to resume normal service.Until this volcano settles down and stops pumping ash, there will be a risk, it really is a changing feast,Wirth said.Qantas will suspend all of its domestic Sydney flights from 0500 GMT, or 3pm local time Tuesday, and Canberra flights from 0200 GMT. Three international flights from Sydney including flight to London and Frankfurt are departing early at 0415 GMT.All other international flights from Sydney scheduled for after 0500 GMT are being reviewed, while another six New Zealand flights have been cancelled, a Qantas spokesman said. That brings the total number of Qantas domestic flights for Tuesday cancelled so far to 73 plus the six New Zealand flights.

Virgin Australia said Canberra flights will be suspended from 0300 GMT. Both airlines have already suspended Adelaide flights.Singapore-based budget carrier Tiger Airways Holdings Ltd. (J7X.SG), which is 33% owned by Singapore Airlines Ltd. (C6L.SG), cancelled all flights scheduled to operate before 0400 GMT and is monitoring the situation.