Qantas said Saturday it has locked out all union employees pending negotiations and canceled all flights around the world.

The cancellations affect 600 flights and 70,000 passengers.

“The lock-out will continue until the [unions] drop the extreme demands that have made it impossible for agreements to be reached,” Qantas said in a statement.

Subsidiary companies Jetstar, QantasLink and Qantas flights operated by Jetconnect will continue, as will freight lines Freighters Australia and Atlas Freighters.

The negotiations are taking place with the Australian Licenced Engineers Union (ALAEA), the Transport Workers Union (TWU) and the Australian and International Pilots Union (AIPA).

Locked out employees will not be paid, with the exception of overseas employees, who will continue to work and be paid. All others will continue to work and be paid.

Full refunds will be available if a customer cancels the flight due to the grounding of the fleet. Deferred travel accomodations will be available.