London, Feb 11 : The emergency call that alerted cops to Chris Brown''s alleged attack on Rihanna features a woman screaming.

Brown, 19, was arrested for felony battery after an alleged incident with the `Umbrella' singer in a vehicle in Los Angeles in the early hours of Sunday morning.

Police have refused to release the tape of the exchange with an operator, reports the Mirror.

But investigator Detective Deshon Andrews said: "It recorded the sound of a screaming woman."

The 20-year-old R&B star yesterday broke her silence over the alleged assault in Los Angeles to insist: "I''m OK."

Both Brown and Umbrella star Rihanna have cancelled forthcoming appearances.

She has also shelved her 21st birthday party. (ANI)