Los Angeles police investigators have identified Rihanna as the victim in Sunday's attack. Brown has been arrested and charged with making criminal threats and Rihanna is cooperating with detectives, the Los Angeles Times reported.

Authorities have said Brown, 19, could face additional charges. He is currently free on bail.

Celebrity magazines and websites have reported that Rihanna, 20, was taken Cedars-Sinai Medical Center in Los Angeles following the incident and has since been released. In recent days, her publicist has issued only one statement saying "Rihanna is well. Thank you for concern and support."

The incident occurred in Brown's car early Sunday, several hours before he and Rihanna were to perform at the Grammy ceremony. Celebrity webstie TMZ.com reported Brown left the scene and police found Rihanna, suffering from a bloody nose, split lip and bite marks, in his car.

Malaysian-based Pineapple Concerts said in a statement on its website that "in light of recent events involving Rihanna" a new date for the concert will be set within two weeks.

E! Online reported a 21st birthday celebration planned for the Barbados-born singer in New York also was canceled.

The National Basketball League said Brown had withdrawn from a celebrity game scheduled for this weekend as part of the NBA all-star game.

Rihanna's hit songs include "Umbrella" and "Disturbia" while Brown's hits include "Forever" and "Kiss Kiss."

(Reporting by Alex Dobuzinskis; Editing by Bob Tourtellotte and Bill Trott)