According to reports, after an unknown source hacked tens of thousands of British Airways (BA) frequent flyer accounts, the airline has locked down all of its attacked accounts. The airline announced about freezing its affected accounts on Sunday.

However, the hacker was not able to access or steal personal details of frequent flyers. BA also expressed apology to its customers and said that their accounts would be freed soon. The source of the hack is not yet known. But, it is assumed that the hacker used a computer program, which infiltrated BA's systems looking for vulnerabilities, before attacking online security.

According to a BA spokesperson, "British Airways has become aware of some unauthorized activity in relation to a small number of frequent-flyer executive club accounts. This appears to have been the result of a third party using information obtained elsewhere on the internet, via an automated process".

The spokesperson also said that they want to tell their customers that currently, they don't know about any access to any subsequent information pages within accounts, which also include payment-card details and travel histories.

According to the airline, they apologize to customers over inconvenience they are facing and the airline is taking the matter seriously and is also taking steps to ensure the security of the accounts.

There have been many cyber-crimes committed earlier also. A group called 'Lizard Squad - Official Cyber Caliphate' attacked Malaysia Airlines in January. According to The Mirror, BA said that it can have the system back up and will be running it in some time. The airline is looking into the matter to ensure the security and find out the sources behind it.