The gunman fired on Labangan Mayor Ukol Talumpa outside Terminal 3 at Manila's Ninoy Aquino International Airport, named after President Benigno Aquino III's father, who was assassinated there 30 years ago. The terminal handles international and domestic flights, and is supposed to be a relatively well-guarded facility. Talumpa had arrived from Zamboanga del Sur, the southern province where Labangan is located.
There was no word on a possible motive, but violent attacks linked to political rivalries, family feuds and business disputes are common in the Philippines, and have left hundreds of people dead over the years. Talumpa himself had survived at least two earlier assassination attempts, according to local media reports.
The mayor and his wife were declared dead on arrival at a nearby hospital along with a 1 1/2-year-old boy and a 25-year-old man, said the airport's general manager, Jose Angel Honrado.
Local radio reports said that the man was a nephew of the mayor, but that the boy was a bystander with no relation to Talumpa.
At least five other people were wounded, including a niece of the mayor and a 3-year-old girl who sustained a head wound, hospital authorities said.
An uncle of the dead boy, Felipe Lirasan, told DZMM radio that the child's family was staying at his home for Christmas. "Then this happened," he said, his voice breaking. "There is nothing that we can do."
Honrado said that investigators were trying to determine how many attackers were involved. Witnesses, however, saw only one gunman, who sped away on a waiting motorcycle that was driven by another man, Honrado said.
An airport car rental dispatcher said one of the two men on the motorcycle was wearing a cap and what appeared to be a police uniform.
"When shots rang out, the passengers all rushed inside the terminal," said the dispatcher, who spoke to a local radio station but didn't give his name.
He said the man wearing the police uniform almost fell off the motorcycle as they sped away. They were chased by airport authorities in cars, but the pair wove their way through the stalled vehicles and escaped, he said.
Local newspapers have reported that Talumpa, then a vice mayor of Labangan, and one of his nephews were wounded in another attack in 2010 in Manila. Last year, assailants lobbed a grenade at Talumpa and his wife in Pagadian City, the capital of Zamboanga del Sur, but they escaped unhurt. Talumpa was elected mayor earlier this year.
Islamic extremists are active in Zamboanga del Sur, but there was no immediate indication that this attack was related to the insurgency.