Twitter faces deepening trouble in India.
The firm's top official in the country has been summoned by police.
That is over allegations that Twitter failed to stop the spread of a video that allegedly incited enmity and hatred between Hindu and Muslim communities.
In the video a group of men, apparently Hindu, are shown beating a man believed to be Muslim.
Now a police case has been registered in the northern state of Uttar Pradesh.
The controversy comes as Twitter locks horns with India's government over its non-compliance with new IT rules.
That has raised doubts over whether the platform will continue to enjoy protection against liability for user-generated content.
Twitter hasn't commented on the police summons.
Earlier this week India's IT minister said it was "perplexing" why the firm hadn't acted to block the video.