Hackers obtained personal information for more than 8,000 pilot applicants at American Airlines and Southwest Airlines after a database maintained by a recruiting company was broken into.

The breach took place at Pilot Credentials, which is based in Austin, Texas, on April 30. 

Both airlines learned about the incident three days later, according to The Associated Press, but told the affected jobseekers last week.

Hackers accessed pilot and cadet applicants' names, birthdates, Social Security and passport numbers, and driver and pilot-license numbers, according to letters the airlines were required to file with regulators.

Filings show that the breach affected 5,745 applicants for American and 3,009 at Southwest. Many of these applicants were hired by the airlines.

A spokesperson for the Allied Pilots Association, a union representing pilots at American, said 2,200 of its members were impacted by the breach. The spokesperson said the union is upset American was aware of the breach for more than seven weeks before the affected victims were notified.

American said it has found no evidence that the information was used for fraud or identity theft, but offered the applicants two years of coverage from a service designed to protect people from identity theft.

Since the breach, the airlines have run their recruitment work through websites they operate instead of using another company.

Both airlines said they are working with law enforcement on the investigation.

The Associated Press contributed to this report.