ATLANTA -- A video of a young woman's profanity-laced tirade on a MARTA train is now the subject of a police investigation.

Captured by another rider, the video of the woman's rant, directed at an elderly MARTA rider, has become an Internet sensation, getting heavy viewing on YouTube.com and other Web video sites.

During the confrontation the young woman refers to herself as "Soulja Girl," repeatedly uses the N-word and threatens the elderly woman.

At first other passengers don't interfere, but after several minutes one man can be heard telling "Soulja Girl" to "chill." Instead of taking that advice she turns on the other passengers, accusing one of rape.

Eventually a male passenger confronts her and appears to knock her wig askew.

After repeatedly screaming "I'm pressing charges, I'm pressing charges," the woman exits the train.

After learning of the video MARTA police launched what they called "an immediate and aggressive investigation into the incident."

After canvassing the East Lake Station where the suspect reportedly exited the train, MARTA police received an anonymous tip that the incident occurred on March 31, between 2 and 4 p.m. The tipster also indicated the suspect has been known to ride Bus 22.

After identifying the suspect, MARTA police have obtained an arrest warrant.

"We want to assure the public that this is an extremely isolated incident and that customer safety and security are our highest priorities," stated MARTA Police Chief Wanda Dunham in a release. "We regret that any customer had to endure such harassment while using our system."

Dunham asked that witnesses to the incident call MARTA detectives at (404) 848-4911.