Facebook has said “almost 50 million” of its users were left exposed by a security flaw.

The company said attackers were able to exploit a vulnerability in a feature known as “View As” to gain control of people's accounts.

Facebook says the breach was discovered earlier this week, and it has informed police.

Users that had potentially been affected were prompted to re‑log‑in earlier today.

The firms head of security, Guy Rosen says the flaw has been fixed, adding all affected accounts had been reset, as well as another 40 million "as a precautionary step".

Facebook has more than two billion active monthly users.

The firm would not say where in the world the 50 million users are, but it has informed Irish data regulators, where Facebook's European subsidiary is based.

[Source:BBC News]