Canadian government officials were trying to determine whether any Canadians were among the casualties of a mass shooting Friday in the baggage area of the airport in Fort Lauderdale, Fla.

The office of Foreign Affairs Minister Stephane Dion said it had no immediate information about Canadian citizens being among the five people reported dead or eight injured after a gunman opened fire.

Air Canada and WestJet had said all their passengers and employees at the Fort Lauderdale airport were accounted for and safe.

A statement from a Florida official that the shooter had travelled to Florida on a Canadian flight sent officials in Ottawa scrambling, but Global Affairs Canada said the shooter had not been a passenger on any Canadian flight, and the plane on which the gunman arrived did not originate in Canada.

Both Global Affairs and the Department of National Defence also said they were not aware of any requests for assistance from U.S. authorities.

U.S. authorities said a man identified as Esteban Santiago was arrested after the shooting inside Terminal 2, which serves Air Canada and Delta. The rampage sparked pandemonium and shut down the airport.

Air Canada and WestJet, which service Fort Lauderdale, said they had no record of any passenger with the name of the suspect or of any checked guns on any of their Friday’s flights to the U.S. city.

We confirm we have no record of a passenger by the name Esteban Santiago, or checked guns, on any of our flights to Fort Lauderdale #FLL 5/5 — Air Canada (@AirCanada) January 6, 2017

“WestJet can confirm that we have no record of the alleged suspect on the passenger manifests for any of our Fort Lauderdale-bound flights,” a spokeswoman said.

A Twitter user from Manitoba named Liam said he was at the airport when the shooting happened.

“Im at the ft lauderdale airport and just went through the most terrifying experience in my life,” read the tweet.

Christian, a Toronto resident who was at the Fort Lauderdale airport waiting to board a flight home when the shooting began, described the ordeal he and his family when through to 680News.

The gunman – identified by authorities as 26-year-old Esteban Santiago, an Army National Guard veteran who served in Iraq but was demoted and discharged last year for unsatisfactory performance – was immediately taken into custody. His brother said he had been receiving psychological treatment recently.

One witness said the attacker gunned down his victims without a word and kept shooting until he ran out of ammunition, sending panicked travellers running out of the terminal and spilling onto the tarmac, baggage in hand.

Others crouched behind cars or anything else they could find to shield themselves as police and paramedics rushed in to help the wounded and establish whether there were any other gunmen. The airport was shut down.

“People started kind of screaming and trying to get out of any door they could or hide under the chairs,” a witness, Mark Lea, told MSNBC. “He just kind of continued coming in, just randomly shooting at people, no rhyme or reason to it.”

Authorities said the motive was under investigation.

Related stories:

Video: Florida airport shooting prompts security questions

Video: Inside baggage claim area after airport shooting

“This could well be someone who is mentally deranged, or in fact it could be someone who had a much more sinister motive that we have to worry about every day, and that is terrorism,” said Sen. Bill Nelson of Florida. “We can’t conclude that.”

President Barack Obama was briefed by his Homeland Security adviser, the White House said.

It is legal for airline passengers to travel with guns and ammunition as long as the firearms are put in a checked bag – not a carry-on – and are unloaded and locked in a hard-sided container. Guns must be declared to the airline at check-in.

Santiago arrived in Fort Lauderdale after taking off from his hometown of Anchorage, Alaska, aboard a Delta flight Thursday night, checking only one piece of luggage – his gun, said Jesse Davis, police chief at the Anchorage airport.

At Fort Lauderdale, “after he claimed his bag, he went into the bathroom and loaded the gun and started shooting. We don’t know why,” said Chip LaMarca, a Broward County commissioner who was briefed by investigators.

The attack exposed another weak point in airport security: While travellers have to take off their shoes, put their carry-on luggage through X-ray machines and pass through metal detectors and full-body scanners to reach the gates, many sections of airports are more lightly secured and more vulnerable to attack.

In 2013, a gunman with a grudge against the Transportation Security Administration shot and killed one of the agency’s screeners and wounded three others during a rampage at Los Angeles International Airport.

Last November, an airline worker was shot and killed near an employee parking lot at Oklahoma City’s airport, and in 2015 a machete-wielding man was shot to death after he attacked federal security officers at the New Orleans airport.

In the Fort Lauderdale attack, Lea said the gunman said nothing as he “went up and down the carousels of the baggage claim, shooting through luggage to get at people that were hiding.” The killer had a handgun and went through about three magazines before running out of ammunition, Lea said.

“He threw the gun down and laid spread-eagle on the ground until the officer came up to him,” Lea said.

The Broward Sheriff’s Office said on social media Friday night that 37 people were injured after the shooting but didn’t give details about how.

Santiago’s brother, Bryan, told The Associated Press that his brother had been receiving psychological treatment in Alaska. He said Santiago’s girlfriend alerted the family to the situation in recent months.

Bryan Santiago said that he didn’t know what his brother was being treated for and that they never talked about it over the telephone.

He said Esteban Santiago was born in New Jersey but moved to Puerto Rico when he was 2. He was deployed to Iraq in 2010 and spent a year there with the 130th Engineer Battalion, according to Puerto Rico National Guard spokesman Maj. Paul Dahlen. He later joined the Alaska National Guard.

The Pentagon said Santiago had gone AWOL several times during his stint with the Alaska National Guard and was demoted – from specialist to private first class – and given a general discharge, which is lower than an honourable discharge.

At the Fort Lauderdale airport, John Schilcher told Fox News said he came up to the baggage claim and heard the first gunshot as he picked up his bag off a carousel.

“The person next to me fell to the ground and then I started hearing other pops. And as this happened, other people started falling and you could hear it and smell it, and people on either side of me were going down and I just dropped to the ground,” said Schilcher, who was there with his wife and mother-in-law. “The firing just went on and on.”

“I was down on the floor. When we finally looked up there was a policeman standing over me,” he said. “That’s when I assumed it was safe.”