Ad for a recent evening at Pulse, where the shooting occurred (Image via Pulse)

UPDATE: The killer has been IDed as 29-year-old Omar Mateen, a U.S.-born man whose parents immigrated from Afghanistan. So unbelievable that a person could be born and raised in this country and hate it and its people.

Early today, a gunman shot and killed at least 20 people and injured another 42 in the packed gay nightclub Pulse in Orlando, Florida. Reports are that the authorities consider it an act of domestic terrorism.

The suspect carried an assault rifle and a handgun, as well as another so-called “device.” A controlled explosion carried out by police after the incident may have been related to the device.

According to patrons, the incident occurred around 2 a.m. A security guard exchanged fire with the shooter before he entered and holed up inside the club with hostages. Police had to storm the place around 5 a.m., killing the man. But it was too late for the victims, and it sounds like the already horrific death toll is set to rise.

Witness describes chaotic scene at Orlando nightclub: "He was shooting everywhere." https://t.co/S9TMfGobhu https://t.co/P91vpE1rVb

— Good Morning America (@GMA) June 12, 2016

Popular drag performer Kenya Michaels was at the club, and has since posted she got out alive:

 The FBI has already noted the shooter may have been a radical Islamist: 

FBI: There are "suggestions" shooter at Orlando nightclub had radical Islamic leanings https://t.co/KoOkTZCAbR https://t.co/hGyZRFXWZk

— ABC News (@ABC) June 12, 2016

So far, there's no word that this is tied to an international group like Islamic State, or whether it was the work of a lone supporter of that or another group, but officials do not believe more attacks are immediately planned for Orlando: 

FBI: No credible information to suggest any further threat to Orlando following shooting. https://t.co/ZdaJMtkE0q pic.twitter.com/2hkuZCsMXN

— ABC News (@ABC) June 12, 2016

There can be no mistaking the timing of the attack, during Gay Pride Month. We need to band together during this terrible time and stay strong. No one's ideology and no one's weaponry will ever silence the LGBT community.

Hillary Clinton reacts to the news:

Woke up to hear the devastating news from FL. As we wait for more information, my thoughts are with those affected by this horrific act. -H

— Hillary Clinton (@HillaryClinton) June 12, 2016