Melbourne:  Flight operations in Australia were severely disrupted on Tuesday in the backdrop of volcanic ash cloud rising from a Chilean volcano, causing inconvenience to over one lakh passengers, who are facing delays in their scheduled travel.

The country's flagship carrier Qantas cancelled its services to Sydney, Canberra and Melbourne for Wednesday, and continued to monitor the flight path between Perth and
Melbourne, reports said. It also cancelled flights to Adelaide last night.

Darwin Volcanic Ash Advisory Centre head Andrew Tupper said the ash had wrapped around a low-pressure system building over south-eastern Australia and had crossed the South
Australian coast early on Tuesday.

It is expected to remain over Sydney overnight but move southward by Wednesday and expectations are that it will clear Australia by Wednesday night.

Australia's two major airports were facing the prospect of being shut down for up to 48 hours as the ash cloud from a Chilean volcano continues to drift across southern Australia.

Other airlines Jet star and Tiger Airways were also forced to ground flights.

Transport Minister Anthony Albanese said Federal Government backs the cancellations in the interests of safety.

He said Civil Aviation Safety Authority (CASA) and Air services Australia are working with the airlines to ensure safety procedures are being followed.

Albanese said the Bureau of Meteorology estimates Adelaide will be affected for 24 hours, Canberra and Sydney for around 36 to 48 hours, and Melbourne for 36 to 48 hours from Wednesday morning.

The ash cloud from Chile's Mount Puyehue Cordon Caulle volcano is circling the earth for a second time, after last week delaying flights across Australia and New Zealand for several days.