Dozens of people died after a gunman whom police described as a robber fired shots and set fires at a casino resort complex in the Philippines.

All of the 36 victims died from suffocation or smoke inhalation after casino tables were set ablaze, Police Chief Oscar Albayalde said.

The attacker also apparently killed himself during the incident at Resorts World Manila in Pasay City, a southwestern suburb of the capital.

Stephen Reilly, the casino's chief operating officer, later said that 35 people had died — 13 employees and 22 guests — in what he described as a "senseless attack." The reason for the discrepancy between the death tolls was not immediately clear.

Earlier, local and national police insisted for hours that only the gunman died in the incident, which began shortly after midnight Friday (noon Thursday ET).

Reilly told reporters that members of the casino's security team were able to shoot and wound the gunman, prompting him to take shelter in a room where he then killed himself.

Soldiers outside Resorts World Manila on Friday. Basilio H. Sepe / Getty Images

Ronald dela Rosa, chief of the Philippines National Police, said the suspect burned himself to death.

President Donald Trump — speaking in Washington, where he announced his decision to withdraw from the Paris Climate Accord — immediately called the incident a "terrorist attack" and said the United States was closely monitoring reports. He didn't say how the United States had determined that the attack was terrorism.

But Dela Rosa told reporters after Trump spoke that there was no indication of terrorism.

The suspect — who was believed to be a foreign white man who spoke English and acted alone — stuffed casino chips into a bag and tried to flee through the main complex, setting casino tables on fire and firing a weapon at a TV set, Dela Rosa said.

The gunman who attacked the Resorts World Manila complex was captured on surveillance cameras. Philippine National Police via AP

Albayalde said the culprit carried a long firearm similar to a "baby ArmaLite" — a term often used in the Philippines to refer to a variant of the M16 carbine.

Dela Rosa and Albayalde said the motive appeared to have been robbery.

Albayalde said the gunman had likely been addicted to gambling and ransacked a storage area where casino chips were stocked. He said the man made off with chips worth about 130 million pesos, or roughly $2.6 million.

Terrorism concerns are widespread in the Philippines, where President Rodrigo Duterte declared martial law across region the size of South Korea last week in response to ISIS-linked militants' besieging the majority Muslim city of Marawi.

But Dela Rosa said the gunman "would have shot at people or triggered a bomb" had he been a terrorist.

Still, he warned, ISIS could falsely try to claim responsibility for propaganda purposes.

We ask for your prayers during these difficult times. — Resorts World Manila (@rwmanila) June 1, 2017

The U.S. Embassy in Manila urged Americans to "exercise caution and review your personal security plans."

Duterte has warned that rebel fighters could try to advance northward as they push their agenda of an independent Islamic state and that he may seek to widen martial law across the entire country.