Global condemnation led by US President Barack Obama, Pope Francis and Queen Elizabeth II after a gunman went on the rampage at a gay nightclub in Florida leaving almost 50 people dead.
The pontiff condemned the killings as 'homicidal folly and senseless hatred' while Obama described them as 'an act of terror and an act of hate'.
According to a tweet from the British royal family's official account, the queen was 'shocked' by the attack, adding that the monarch and her husband's 'thoughts & prayers are with all those who have been affected'.
Leaders from countries shaken by recent jihadist attacks, including France and Belgium, were among the first to express solidarity with the US.
Afghan President Ashraf Ghani sent his condolences to the families of the victims as authorities identified the alleged gunman as 29-year-old Omar Mateen, a US citizen of Afghan descent.
'I unequivocally condemn the horrific attack in Orlando, Florida, USA. Nothing can justify killing of civilians,' Ghani tweeted.
In a statement from the Holy See, the pope lamented the tragic loss of life.
The attack had 'caused in Pope Francis, and in all of us, the deepest feelings of horror and condemnation… before this new manifestation of homicidal folly and senseless hatred', said the statement.
n France, which remains on edge after Islamic State group jihadists killed 130 people in Paris in November 2015, President Francois Hollande reacted "with horror".
The president 'expresses the full support of France and the French people to the US authorities and the American people during this ordeal', a statement from the Elysee Palace said.
Prime Minister Manuel Valls also expressed his 'compassion" and "solidarity with the American people.
"By striking the gay community, this terrible Orlando attack reaches us all," he wrote in French on Twitter.
Belgium's Prime Minister Charles Michel tweeted his condolences over the attack, which comes two-and-and-half months after dual strikes by jihadists on Brussels airport and metro that killed 32 people.
"Deeply saddened by the loss of so many innocent lives in Orlando shooting. We join families in their grief," he said.
In Britain, Prime Minister David Cameron said on Twitter he was 'horrified' by the shooting.
"On behalf of the people and government of Israel I extend our deepest condolences to the American people following last night's horrific attack on the LGBT community in Orlando," he said in a statement issued in English.
Russian President Vladimir Putin, meanwhile in a Kremlin statement, called the killings 'a barbaric crime'.
Bollywood celebrities Farhan Akhtar, Priyanka Chopra, Rishi Kapoor, Sonam Kapoor, Shahid Kapoor among others expressed their condolences for the victims of the mass shooting at a gay nightclub in Orlando.
