It also said it had separately removed a network of about 40 fake accounts, groups and pages across Facebook and Instagram targeting people in Ukraine, for violating its rules against coordinated inauthentic behavior.

In a blog post on Monday (February 28), Meta attributed the hacking efforts to a group known as Ghostwriter, which it said successfully gained access to the targets' social media accounts.

Meta's security team said it had taken steps to secure targeted accounts and had blocked the phishing domains used by the hackers.

It declined to give the names of any of the targets but said it had alerted users where possible.

A spokesperson for Twitter said it had also suspended more than a dozen accounts and blocked the sharing of several links for violating its rules against platform manipulation and spam.

The crisis in Ukraine has seen escalating clashes between Moscow and big tech. On Friday (February 25) , Russia said it would partially restrict access to Facebook. Twitter also said its service was being restricted for some Russian users on Saturday (February 26).