NEW YORK (CBSNewYork/AP) — Politicians are speaking out and offering their support for the people of Orlando following a mass shooting at a nightclub early Sunday morning.

Police confirmed at a news conference Sunday morning that 50 people were killed, up from 20 as earlier reported. The massacre is now the worst mass shooting in U.S. history.

PHOTOS: 50 DEAD IN ORLANDO NIGHTCLUB ATTACK

Officials said 53 more are hospitalized after the incident and said the shooter is among the dead.

Earlier Sunday morning, presumptive Democratic nominee Hillary Clinton took to Twitter, calling the massacre a “horrific act.”

“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,” she said.

Republican presumptive nominee Donald Trump also posted on Twitter about the “Really bad shooting in Orlando.”

“Police investigating possible terrorism,” he said. “Many people dead and wounded.”

“Horrific incident in FL,” Trump tweeted later. Praying for all the victims and their families. When will this stop? When will we get tough, smart and vigilant?”

Democratic presidential candidate Bernie Sanders called the murders “horrific” and “unthinkable” while speaking early Sunday to NBC’s “Meet the Press.”

“Our — just — hopes go out to all those who were shot that they can recover,” Sanders said.

Former presidential candidate Florida Sen. Marco Rubio also called it “horrifying act” and tweeted a call to central Florida residents to donate blood for those who were injured in the shooting.

The White House said President Barack Obama has been briefed and has asked for regular updates as the FBI and other federal officials work with Orlando police on the case.

Press secretary Josh Earnest said in a statement that the president has directed federal officials to provide “any necessary assistance to pursue the investigation and support the community.”

The White House also issued a statement from Vice President Joe Biden’s spokesperson, calling the shooting a “heinous attack.”

“Vice President Biden offered his prayers for all those killed and injured in the shooting and sends his condolences to all the families and loved ones of the victims,” the statement said.

Rep. Sean Patrick Maloney, the first openly gay member of Congress, called for a “serious and rigorous conversation” on the threat of anti-LGBT violence in the United States in the wake of the attacks.

“These are important debates and it is precisely what our political system should respectfully encompass,” Maloney said in a statement Sunday. “But in the immediate aftermath of this tragedy, it is my hope that our first response will be to remember our common concern for the victims and those who love them.”

The Vatican released a statement Sunday on behalf of Pope Francis, expressing feelings of “horror” and “condemnation:”

“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 or horror and condemnation, of pain and turmoil before this new manifestation of homicidal folly and senseless hatred.”

CBS News reports Mateen has no apparent criminal history and that authorities are investigating whether he had ties to Islamic terrorism.

(TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)