Editors' Note: This post has been updated. More information will be included as it becomes available.

A gunman carrying an assault rifle and a handgun stormed an Orlando, Fla., crowded bar early on Sunday and killed at least 50 people in what has become the deadliest mass shooting in U.S. history.

U.S. law enforcement officials identified the shooter as Omar Mateen, a 29-year-old American citizen who worked as a security guard and had pledged allegiance to the Islamic State before the attack.

Police say Mateen entered Pulse nightclub around 2 a.m., exchanged fire with an off-duty police officer working security at the club, then began shooting wildly into the crowd. The shooting turned quickly into a hostage situation until police, using an armed vehicle, assaulted the club and killed Mateen.

"This was an act of terror and an act of hate," President Obama said in remarks delivered on Sunday. "The shooter targeted a night club where people came together to be with friends, to dance and to sing, and to live. The place where they were attacked is more than a nightclub. It was a place of solidarity and empowerment, where people have come together to raise awareness, to speak their minds and to advocate for their civil rights."

Within hours of the shooting, the racist right responded with attacks on the LGBT community and immigrants.

“I don't know anything about the motives or the shooter at this point, but considering how violent f--- are, it wouldn't surprise me if its [sic] a disgruntled f-- who's butt buddy went into the restroom with a different f--," a user named “Crowe” wrote on the Vanguard News Network forum just hours after the shooting. Crowe added, “[R]egardless of the shooter's motives, I'm hoping for as many casualties as possible,”

Andrew Anglin, editor and publisher of the racist website Daily Stormer, also joined in, writing on his website, “Let this be the start of the terrorist/f----- civil war."

The response also focused heavily on attacking Muslim immigrants –– a prevalent theme in the midst of a presidential campaign punctuated by calls to build a wall on the U.S. border with Mexico, as well as ban Muslims from entering the United States.

Michael Hill, president of the neo-Confederate League of the South (LOS), a group that for years has played with fantasies of becoming a paramilitary organization, voiced support for deporting Muslims and arming citizens in response.

"In a free & independent South, Islam would be banned, Muslims deported, and all mosques closed down. The ownership of firearms, including military grade, would be encouraged for all Southern citizens in order to protect the public from such incidents as occurred overnight in Orland, Florida," Hill wrote in a statement posted to the LOS website.

The shooting comes just two weeks after President Obama declared June “Lesbian, Gay, Bisexual, and Transgender Pride Month.” Orlando scheduled its Pride celebration to take place next weekend.