(Repeats story first published on Sunday; no change to text)
By Morag Mackinnon
PERTH, June 1 (Reuters) - Australian airlines forced to cancel flights due to a volcanic ash cloud from Indonesia's Sangeang Api volcano resumed flying on Sunday as the plume cleared.
With the threat to Australian airspace now abating, the continuing low-level eruption of the volcano in the Sunda Islands in southern Indonesia may pose a threat to the airspace around Bali in the coming days, the agency tasked with monitoring ash in that airspace told Reuters.
"With the volcano continuing to erupt, we can still see a significant amount of ash around the volcano," Emile Jansons, manager of the Darwin Volcanic Ash Advisory Centre told Reuters.
"Our biggest concern at the moment is that the boundary of the ash cloud is not very far away from Bali and if there is another larger eruption then the ash could move and affect that airspace."
A large eruption of Sangeang Api on Friday sent an ash cloud high into the atmosphere that moved across northern Australia, causing the cancellation of some flights between Australia and Southeast Asia and all domestic flights operating out of Darwin airport on Saturday.
The volcano is sustaining a weak eruption and the ash cloud above it is reaching just 5 kilometres (3.1 miles) above sea level, compared to 10 kilometres (6.2 miles) on Friday, Jansons said.
Volcanic ash can be extremely dangerous to aircraft and cause engine failure or engine damage. Airlines each apply their own risk assessment criteria in deciding whether to fly.
Operations at Darwin International Airport were getting back to normal on Sunday afternoon with regional carrier Airnorth having resumed flights and the major airlines resuming mid-afternoon, spokeswoman Virginia Sanders said.
Qantas Airways Ltd tweeted that its operations in and out of Darwin had resumed and its budget carrier Jetstar also said in a statement that its services to and from Darwin were set to resume.
In a later advisory from the airline on Sunday night, Jetstar said it had cancelled 12 flights in and out of Bali's capital Denpasar for Sunday and Monday "as the ash cloud emanating from Sangeang Api drifts toward Denpasar International Airport."
The ash cloud from the continuous, low-level eruption of Sangeang Api was 100 nautical miles south, southeast of Bali late on Sunday at a height of 10,000 feet, Cyndee Seals from the Darwin Volcanic Ash Advisory Centre told Reuters.
Virgin Australia Holdings spokeswoman Jacqui Abbott said the airline had made a rigorous risk assessment and all flights were resuming after Saturday's cancellations.
"The safety of our guests is our highest priority and our team of meteorologists are continuing to monitor the situation, in close consultation with the Volcanic Ash Advisory Centre," Virgin said in a statement.
Indonesia's Sunda Islands lie along the collision of two tectonic plates and are among some of the most geologically active regions in the world. (Reporting by Morag MacKinnon; Editing by Matt Driskill)