ORLANDO – Key American Muslim figures, scholars and organizations have condemned the deadly shooting spree at a nightclub in that city that left 50 people dead, urging the Muslim community to take part in a blood donation drive for those injured in the attack.

“We condemn this monstrous attack and offer our heartfelt condolences to the families and loved ones of all those killed or injured,” Rasha Mubarak, Regional Coordinator of Orlando, Florida chapter of the Council on American-Islamic Relations (CAIR-FL), said in a statement obtained by AboutIslam.net.

“The Muslim community joins our fellow Americans in repudiating anyone or any group that would claim to justify or excuse such an appalling act of violence,” she added.

A gunman killed 50 people at a packed gay nightclub in Orlando, Florida on Sunday and wounded 53 others before being killed by police in the worst mass shooting in US history.

The shooter was identified as Omar S. Mateen, a Florida resident who a senior FBI official said might have had leanings toward Islamic State militants.

Officials called the rampage a “terrorism incident,” but cautioned that the suspected Islamist connection required further investigation.

Orlando Mayor Buddy Dyer said the attack was the deadliest single US shooting incident, eclipsing the 32 people killed in the 2007 massacre at Virginia Tech University.

Muslim leaders rushed to condemn the attack as barbaric.

‪”#‎Orlando Senseless. Barbaric. Despicable. As the shouting wars begin on television and social media, don’t forget the grief of the families who woke up to the news that their loved ones were ruthlessly taken away from them. Our thoughts and prayers are with them today. We condemn this unspeakable horror,” Omar Suleiman, a Muslim scholar, wrote on Facebook.

“We just spent a week honoring a man, well known to us, who was inspired by Islam to spread peace & justice to every corner of this world, touching millions of lives in a beautiful way.

“I, and Muslims across this country, refuse to be involuntarily represented by some demented murderer unknown to us who ruthlessly took the lives of tens of people in Orlando today,” he added.

Linda Sarsour, another American Muslim activist, has also expressed sadness over the attack.

“Woke up to horrible news. Sending love to LGBTQI communities everywhere. Please pray for the victims and their families,” she wrote on Facebook.

“The words are not flowing. In horror & shock. Please let us know how we can support. ‪#‎OrlandoShooting.”

President Barack Obama called the mass shooting an “act of terror” in remarks to the nation from the White House briefing room.

“We know enough to say this was an act of terror and an act of hate,” he said.

“The FBI is appropriately investigating this as an act of terror. We will go wherever the facts lead us … What is clear is he was a person filled with hatred.”