Rihanna heard screaming on 911 call

More terrifying details emerge over Rihanna and Chris Brown's aggressive fight on Sunday night

Singer Rihanna was allegedly 'heard screaming' during the 911 call which alerted police to her aggressive fight with boyfriend Chris Brown on Saturday night.

Although police have still refused to confirm who Brown attacked during the incident in Los Angeles at the weekend, Rihanna has not been seen since and family and friends have come forward to offer support for the R&B star, while American radio stations are banning Brown's own tracks from their airwaves.

TMZ.com reports that Rihanna received medical care at the Cedars-Sinai Medical Center in LA on Sunday where she sported swelling and bruising on her face and bite marks on her arms and hands.

As well as missing Sunday night's Grammy Awards, Rihanna has cancelled a sell-out concert in Kuala Lumpur, Malaysia, which was due to take place this Friday, and her upcoming 21st birthday party.

The tape of the 911 call has not been released to the media, however, LAPD chief investigator Detective Deshon Andrews did tell reporters: 'It mostly recorded the sound of a screaming woman.'

Sergeant Bridget Pickett, also from the LAPD, said Brown – who is currently free on $50,000 bail – was arrested over 'criminal threats' but that 'domestic violence charges' could be added later.

Kanye West yesterday told People magazine: 'I feel like, just as a person, I don't care how famous she is or even if she just worked at McDonald's, that should never happen. It should never come to that, to that place.'

Meanwhile, Brown's former stepfather, who he claims used to abuse his mother, told Access Hollywood he 'wouldn't be surprised' if Brown had harmed his girlfriend and that he 'has to take responsibility for his own actions'.