Qantas Airways Ltd. is furloughing an additional 2,500 workers as state border controls inside Australia to stem Covid-19 outbreaks destroys air travel.

The airline said Tuesday it expects flights in and out of Sydney in New South Wales state—which is fighting its biggest virus flareup—to be closed for at least another two months. That’s weeks after the scheduled Aug. 28 end to the city’s lockdown.

“We’re now faced with an extended period of reduced flying,” Chief Executive Officer Alan Joyce said in the statement. “It will take a few weeks once the outbreak is under control before other states open to New South Wales and normal travel can resume.”

The announcement takes total furloughed staff at Qantas to 9,500, including around 7,000 at the airline’s international business. The latest outbreak has put Qantas’ recovery from the pandemic into reverse as authorities wrestle with the highly infectious delta variant.

Qantas and its low-cost unit Jetstar had operated at close to pre-pandemic levels in May, before lockdowns in three Australian states cut domestic flying to less than 40% of normal volumes in July.

Workers who are stood down, or furloughed, remain Qantas employees but won’t be paid a salary. The airline’s current workforce is about 22,000.