The security footage shows the man responsible for one of the Philippine capital's deadliest attacks in years casually exiting a taxi just after midnight and walking calmly into a vast entertainment and gambling complex like any other visitor.

Shortly afterward, he dons a black mask, slips on an ammunition vest and pulls an M4 carbine assault rifle out of his backpack.

What follows borders on the surreal: a slow-motion arson attack and robbery so methodical and unhurried, the gunman appears to walk much of the way — even as he exchanges fire with security forces and flees, slightly wounded, up a stairwell.

The Islamic State group claimed responsibility for the early Friday rampage at the Resorts World Manila complex; at least 37 patrons and employees died, mostly from smoke inhalation while they hid, while the gunman fled to an adjoining hotel and reportedly killed himself.

But authorities say the video footage shown to reporters Saturday by Resorts World bolsters the government's case that this was a botched robbery by a lone attacker with no known link to terrorism.

In his first remarks on the assault, Philippine President Rodrigo Duterte said Saturday that the attacker was simply "crazy," questioning what the gunman was going to do with the $2 million horde of poker chips he had tried to haul away. Duterte discounted any links to the Islamic State group, saying this "is not the work of ISIS. The work of the ISIS is more cruel and brutal."

Despite several initially contradictory accounts of the chaos, what is known so far appears to back up that claim.

Although the attacker was well armed — Manila police chief Oscar Albayalde said he was carrying 90 bullets in three rifle clips — there are no confirmed reports that he shot any civilians. Instead, he fired warning shots into the ceiling that scattered panicked crowds, some of whom jumped out windows to escape what they believed to be a terror attack.

More than 12,000 people were in the complex at the time; most were successfully evacuated.

"He could have shot everybody there," Albayalde said. "He could have killed hundreds of people inside that establishment. But he did not shoot anybody ... he just burned the casino. Burning the casino could be a diversionary tactic for his escape."

"All indications ... point to a criminal act by an apparently emotionally disturbed individual," he added.

By nightfall Saturday, the gunman's identity was still unknown. But police were interrogating the taxi driver who dropped him off. The driver said his passenger spoke fluent Tagalog and appeared normal during the ride. The gunman asked him to change the radio channel to the news instead of music, Albayalde said.

National Police Chief Ronald dela Rosa also said the attack did not appear to be terrorism, but he cautioned that authorities still know very little about the attacker.

"What if we establish the identity and there are leads that will lead toward terrorism? So our findings, our conclusion, will possibly change," he told DZMM radio.

The Philippines has faced Muslim insurgencies for decades, though much of the violence has occurred in the troubled south. Many in Manila fear Friday's attack is linked to ongoing battles with militants aligned with the Islamic State group in the southern Philippine city of Marawi. The fighting has placed much of the country on edge, prompted Duterte to declare martial law across the south and raised fears that the insurgents are gaining a foothold in the country.

IS has carried two statements claiming responsibility for the attack, but there have been discrepancies. One mentioned fighters, the other just one fighter — a person who goes by the nom de guerre "Brother Abu al-Kheir al-Arkhabili." One of the statements also said the attacker "died as a martyr" — which would not make sense if he shot himself in an evacuated hotel room at the end of the night, as the police claim. Suicide is forbidden in Islam.

Amreen Gomez, a security officer at Resorts World Manila, said witnesses interviewed had testified to seeing multiple assailants. But he believes their accounts were likely confused by the chaos and panic they experienced. Beyond the unidentified gunman, the only other people armed in the images released Saturday were the security forces clearing the area.

When the security footage begins, it shows the man entering the complex at a taxi drop-off zone with no weapon visible. He's then seen in an elevator, dressed in black with a backpack, with two women behind him. He exits, pulls the weapon out of his backpack and enters the second-floor casino, bypassing the metal detector. As a security officer runs after him, the first crack of automatic weapons fire is heard.

With clear determination, he begins circling the room, dousing gambling tables and then igniting each one with a lighter. He moves on to the dining all, and the slot machines, setting fires as he goes.

Luchie Arguelles, 61, was playing slots just after midnight when she saw the man enter. "(He was) all dressed in black, burly, everything was covered, you can't even see his eyes," said Arguelles, who was about 9 meters (30 feet) from the gunman. She said he was holding two small bottles.

"I said, 'He's going to burn that table, he's going to douse it,'" before she grabbed her husband's hand and started running.

The remaining footage shows the gunman repeatedly shooting bursts of rifle fire into several locked white doors and finally breaking into one. Apparently looking for cash, he finds only poker chips, and hauls a stash away.

In the final scenes, he is exchanging fire with security forces tracking him through a stairwell. The assailant is shot in the leg, but makes it up three flights to a red-carpeted hotel corridor, where he sets something at the far end on fire. Hotel security had already evacuated guests from the floor.

At 1:46 a.m., he breaks into an empty room and sets it on fire, too. Security forces soon arrive, aiming the white lights on their weapons through the smoke-filled hallway.

The attacker, they say, was found in the room with a gunshot wound to the mouth. Authorities declined to show the man's final image, saying it was too gruesome.