NEW YORK (REUTERS) - The US Federal Aviation Administration (FAA) said on Sunday that a software upgrade at an air traffic centre in Leesburg, Virginia, may have led to more than 440 flights getting cancelled on the heavily populated US East Coast on Saturday.

Travel at airports affected by the glitch resumed normal operations by Saturday evening after tens of thousands of passengers were affected by flights up and down the Atlantic Coast being cancelled or delayed.

In a post on Facebook, the FAA said it had disabled the new features added from the upgrade until it completes its investigation.

There is no sign that the automated software that was upgraded has any "inherent problems," the FAA said.