"Based on what we know right now, we believe approximately 130 accounts were targeted by the attackers in some way as part of the incident. For a small subset of these accounts, the attackers were able to gain control of the accounts and then send Tweets from those accounts," Twitter Support said.
The investigation into the incident is still ongoing with Twitter working with the owners of impacted account to establish whether "non-public data related to these accounts was compromised" by hackers.
Earlier this week, Twitter detected what it believes to be a coordinated social engineering attack by those who successfully targeted some of the social network's employees with access to internal systems and tools.
As part of the response, Twitter is now blocking any accounts that had attempted to change their password over the past 30 days, though there is no evidence that attackers accessed passwords.