Swift Political Reactions to Deadly Orlando Club Attack The presidential candidates and elected officials are weighing in.

 -- Politicians are weighing in on news of the deadly terror attack in a Florida nightclub early this morning.

President Obama was briefed on the "tragic shooting," according to the White House.

Other politicians started responding when it was first believed that there were 20 fatalities, but officials have now reported that at least 50 people were killed and 53 others were treated for injuries.

Presumptive Republican presidential nominee Donald Trump was the first candidate to tweet about the incident, which officials have called an "act of terror," though it remains unclear if it was a domestic or international terror attack.

Presumptive Democratic presidential nominee Hillary Clinton also tweeted her thoughts, signing the message with an "-H" which is used to denote tweets she writes herself.

Sen. Bernie Sanders called the shooting "horrific" and "unthinkable" during an appearance on "Meet the Press."

"We have got to do everything that we can to prevent guns from falling into the hands of people who should not have them," Sanders said.

Rep. Alan Grayson, whose district includes the area of Orlando where the shooting occurred, offered his thoughts for the victims.

"Words cannot express the horror, pain and sadness that we feel about this terrible loss. I commend the Orlando police for their heroic efforts to save the lives of those who could be saved," Grayson said in a statement.

Other Florida politicians also tried communicating with their constituents, including both Gov. Rick Scott and Sen. Marco Rubio who tweeted their prayers. Scott said that the state would "devote every resource available to assist" and Rubio called for action.

On ABC News' “This Week,” Terry DeCarlo, the executive director for GLBT Center of Central Florida, said that it remains unclear whether the club was targeted specifically because it is a gay nightclub.

“There’s a lot of traumatized people here right now. We have mobilized our center, we’ve thrown open our doors. We have counselors heading there right now,” he said.

“This is just a tragic situation, we’re trying to find out exactly what’s going on and wrap our heads around how something like this could possibly happen,“ DeCarlo said.

“It is an LGBT nightclub, it’s one of the largest LGBT nightclubs here in Orlando. We cannot say that it was a specific hit on an LGBT nightclub right at the present time. The police are working on that,” DeCarlo added.

Pope Francis weighed in on the massacre, issuing a statement by Holy See press officer Father Federico Lombardi.

"The terrible massacre that has taken place in Orlando, with its dreadfully high number of innocent victims, has caused in Pope Francis, and in all of us, the deepest feelings of horror and condemnation, of pain and turmoil before this new manifestation of homicidal folly and senseless hatred," the statement reads.

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