Friends and family members embrace outside the Orlando Police Headquarters during the investigation of a shooting at the Pulse nightclub in Orlando, Florida. Thomson Reuters The Orlando nightclub gunman made two trips to Saudi Arabia between 2011 and 2012 for the Muslim religious pilgrimage known as Umrah, NBC reported Monday.

A US official told CNN's Jim Sciutto that the gunman also traveled to the United Arab Emirates around that time.

"Orlando shooter traveled to Saudi Arabia and UAE in 2011-12, US official tells me," Sciutto tweeted. "Saudi Arabia interior ministry adds that he went for the Umrah, the lesser religious pilgrimage that can take place any time of year."

The shooter, identified as Omar Mateen, killed 49 people at a gay nightclub in central Orlando early Sunday morning. Mateen called 911 sometime during his rampage and pledged allegiance to ISIS, mentioning the Boston Marathon bombers during the call.

The ISIS-affiliated news agency Amaq News broadcast a claim of responsibility from the terror group for the rampage late Sunday afternoon.

Mateen's father, Mir Seddique Mateen, told NBC News that his son's actions had "nothing to do with religion." He said his son became angry when he saw two men kissing in Miami months ago, and he said he believed homophobia may have inspired his son to attack the nightclub.

The imam at the Islamic Center of Fort Pierce, where Mateen often went to pray, told reporters in Fort Pierce that Mateen "was the most quiet guy — he never talked to anyone." He said later that Mateen had come to the mosque with his 3-year-old son and his father the night before the shooting, and "was the last to come in and the first to leave."

A photo from Omar Mateen's MySpace page. Screenshot/MySpace

One of Mateen's friends, however, told The Washington Post on the condition of anonymity that Mateen had indeed traveled to Saudi Arabia for a religious pilgrimage after a divorce from his wife.

"He was quite religious," the friend said, but added that Mateen never expressed support or sympathy for radical terror groups like ISIS.

Mateen's ex-wife, for her part, told The Washington Post that he was abusive and "was not a stable person."

"He beat me," she said. "He would just come home and start beating me up because the laundry wasn't finished or something like that."

The leader of Orlando's Islamic faith community, Muhammad Musri, urged people not to rush to judgment or "sensationalize" the shooting.

"I call on my fellow faith leaders ... please pray for the victims and their families at this hour," he said during a press conference. "I want to caution anyone from rushing to judgment or sensationalizing the story, because we do not want the focus of the story to shift from what it is: a horrible tragedy. We are mourning, we are heartbroken."

Sunday's shooting at Pulse nightclub is the deadliest shooting in US history, with more fatalities than the mass shooting at Virginia Tech in 2007 (32 dead) and the mass shooting at Sandy Hook Elementary School in Newtown, Connecticut, in 2012 (27 dead).

Mateen, a US citizen, was born in New York in 1986 to parents from Afghanistan. An FBI representative said he "was organized and well prepared" for the attack on the nightclub. Mateen worked as a security guard in Fort Pierce and rented a car to drive to Orlando. He was armed with an AR-15 assault rifle and a handgun.

Orlando police officers seen outside of Pulse nightclub after a fatal shooting and hostage situation where 49 people died on June 12 in Orlando, Florida. Gerardo Mora/Getty Images

Mateen was on an FBI list of suspected ISIS sympathizers and was looked into by federal authorities once in 2013 and again in 2014. He was the subject of a brief FBI investigation in 2014 before the case was closed.

"The FBI first became aware of Mateen in 2013, when he made threats to coworkers, including possible ties to terrorist activities," an FBI spokesman said Sunday in a news conference.

"In 2014, Mateen again came to the attention to the FBI because of possible ties to an American suicide bomber, Moner Abusalha. The FBI interviewed Mateen and determined that contact was minimal and did not constitute a substantive threat at the time."

Mateen had a Florida license to carry concealed weapons and legally purchased the two firearms used in the attack in the days before, police confirmed Sunday.