ORLANDO, the United States, June 15 (Xinhua) -- A U.S. Federal Bureau of Investigation (FBI) official said on Wednesday the shooting massacre at a gay nightclub in Orlando, Florida was both hate crime and an act of terror.

"This was an act of violence, born out of hate, that inflicted terror on an entire community,"said Ron Hopper, special FBI agent in charge of the case, at a press conference. "So I would call it a hate crime. I would call it terrorism. It's both."

At least 49 people were killed and 53 other wounded, including a police officer, early Sunday morning in a shooting spree at a popular LGBT nightclub in Orlando, Florida. It was the worst mass shooting in U.S. history and the deadliest terror attack since the 9/11 terror attacks in 2001.

The gunman, identified by authorities as Omar Mateen of Port St. Lucie, Florida, was found dead inside the nightclub after a shootout with the police.

Hours after the incident on Sunday, U.S. President Barack Obama called it "an act of terror and hate."

Meanwhile, according to U.S. TV network NBC News, Mateen's wife had reportedly feared that Mateen was planning to attack a gay nightclub before Sunday's massacre and pleaded with him not to commit violence, but she did not warn to the police.

Speaking at the press conference, Hopper said so far Mateen remained the main suspect in the FBI investigation.