New York - (AFP) - The US Civil Aviation Authority confirmed Thursday that the technical failure that forced it to temporarily suspend all domestic flights in the United States on January 11 was caused by a contractor mistakenly deleting files.

The authority previously reported that a database file corruption caused the malfunction and led to the delay and cancellation of thousands of boot operations on January 11.

The authority said Thursday that an initial report showed that one of the subcontractors "inadvertently erased files while working on synchronization between the main database and the backup database."

The investigation continues, but the authority confirms that it has not found any evidence linking the incident to a planned act or cyberattack.

The US Civil Aviation Authority is taking measures to ensure that the information system in question, which aims to warn flight crew members of potential dangers on the ground or in the air in real time, is "more robust".

US Transportation Secretary Pete Buttigieg said on January 11 that he had asked the US Civil Aviation Authority to identify the causes of the problem and explain why the alternative systems that were supposed to work did not work in the event of problems.