Fifty-four others were injured in the attack at the Resorts World Manila.
The bodies were found on the second and third levels of the hotel but most of victims were in the casino area, local media quoted sources from the Bureau of Fire Protection.
The suspect in the attack was later found in a hotel room, dead from an apparent suicide, according to officials who said the unidentified man burned himself alive. A small rifle and another firearm were recovered in the room.
Shortly after the attack, the Manila International Airport Authority raised its security level alert to its highest level, “red”, at the Ninoy Aquino International Airport located directly opposite the resort. Airport operations, however, reminded normal.
Police Chief Director Ronald dela Rosa told reporters the injured at the resort sustained mostly minor injuries and were taken to four area hospitals.
A security guard accidentally shot himself in the chaos and many of the victims experienced breathing difficulties from heavy smoke from the fire.
A top official assured victims they would receive help from management.
An employee identified as Johnny, who works at the casino at the Resorts World Manila, told a local radio station he saw three tables set ablaze by at least one attacker who was wearing a scarf around his head with only his eyes exposed.
Johnny said apart from patrons screaming in panic, he did not hear the attacker identify himself or shout during the attack.
Resorts World said in a statement that the company “is working closely with the Philippine National Police to ensure that all guests and employees are safe”.
Police downplayed a claim mentioned on the SITE Intelligence Group that Daesh claimed the attack was carried out by one of its “lonewolf soldiers”. SITE monitors terrorist groups.
Dela Rosa said there is no indication the shooting was terror related and that investigators are looking alternative possible motives.
“We’re looking at robbery as an angle because he stole, he barged into the storage room for casino chips,” dela Rosa told reporters. “He took the chips, put them inside his backpack but eventually left it. The backpack was recovered by the police.”
The suspect was carrying a liter of gasoline that he poured onto gambling tables that were then set on fire, according to dela Rosa. The suspect reportedly did not aim his weapon at anyone during the attack.
Deash terrorist organization claimed "lone wolf soldiers" from its group had carried out the attack.
Resorts World Manila is a huge complex with more than four hotels, a shopping mall, casino, cinema and theater.