FORT LAUDERDALE, Fla. -- An arriving airline passenger pulled a gun from his luggage and opened fire in the baggage claim area at the Fort Lauderdale airport Friday, killing five people and wounding eight before throwing his weapon down and lying spread-eagle on the ground, authorities and witnesses said.

Chip LaMarca, a Broward County commissioner who was briefed on the attack by the sheriff's office, told The Associated Press that the shooter had arrived aboard a Canadian flight with a gun in a checked bag.

However, Air Canada said it has no record of any passenger with the name of the suspect nor of any checked guns on any of its flights to the city.

"We can confirm that we have no record of such a passenger by that name, or checked guns, on any of our flights to FLL," the tweet said.

LaMarca said of the suspect: "After he claimed his bag, he went into the bathroom and loaded the gun and started shooting. We don't know why."

The attack took place at Terminal 2, which serves Delta Air Lines and Air Canada.

Under Canadian air-safety rules, passengers can only pack firearms in their checked baggage provided the weapons are unloaded and in a locked, hard-sided container. Passengers must also declare the firearms at check-in.

The suspect in the shooting was immediately taken into custody.

Authorities gave no details on a possible motive for the shooting, which sent panicked passengers running out of the terminal and onto the tarmac, baggage in hand, and forced the shutdown of the entire airport.

"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."

Sen. Bill Nelson of Florida said that the gunman was carrying a military ID that identified him as Esteban Santiago, but that it was unclear whether the ID was his. Nelson gave no further information on the suspect.

"We don't know a motive at this point," he said. "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. We can't conclude that."

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

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 of ammunition, Lea said.

Then the attacker threw down his weapon and lay spread-eagle on the ground until he was taken into custody, Lea said.

Sheriff Scott Israel said five people were killed and eight were wounded. Their condition was not disclosed. He said the gunman was arrested unharmed, with no law enforcement officers firing any shots, and was being questioned by the FBI.

People spilled onto the tarmac, some carrying luggage, and some ran from both Terminals 1 and 2, hiding behind cars or anything else they could find to shield themselves.

The airport suspended operations as law enforcement authorities rushed to the scene and emergency medical workers treated at least one bleeding victim on the tarmac. Fort Lauderdale-bound flights already in the air were delayed or diverted, and those that had yet to take off from the airport were held on the ground.

Video posted on Instagram appeared to show several people wounded in the baggage claim area of the terminal. One person appeared to be lying in a pool of blood with a head wound.

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," he said.

He said the gunman emptied his weapon and reloaded, and "it was eerily quiet."

"I was down on the floor, when we finally looked up there was a policeman standing over me," Schilcher said. "That's when I assumed it was safe."