MANILA - A Philippine mayor known for parading drug suspects through the streets of his city was shot dead as he presided over a flag-raising ceremony at the city hall early on Monday (July 2).

Police said Mr Antonio Halili, mayor of Tanauan city, 66km south of the capital Manila, was shot in the chest, possibly by a sniper, at around 8am.

The 72-year-old died on the way to a hospital 45 minutes later.

"The bullet went through his chest," Superintendent Renato Mercado, Tanuan police chief, said in a radio interview.

Director-General Oscar Albayalde, the national police chief, said investigators had no leads yet, but that a task force was being formed to look into the killing.

Mr Halili was stripped of his supervisory powers over local police last October (2017) due to a proliferation of illegal drugs in his city.

He was on a list of "high-value targets" linked to drugs released in 2017 by the National Police Commission.

But he denied allegations that he was involved in the drugs trade.

He backed President Rodrigo Duterte's war on drugs, and was known for his "walk of shame" for suspected drug dealers.

In a statement, Mr Duterte's spokesman Harry Roque said Mr Halili was a "a staunch ally in the war on drugs. He was an exemplary mayor. It's a big loss".

But in a speech later in the day, Mr Duterte contradicted his spokesman.

He said he suspects Mr Halili had ties to the drug trade, and that the slain mayor's "shame campaign" was merely "a pretence".

Mr Halili was the fourth local politician to be killed in the government's controversial drug war, which has left over 5,000 dead since June 2016.

In July 2017, police killed Mayor Reynaldo Parojinog, of Ozamiz city, in the war-torn southern island of Mindanao, during a series of pre-dawn anti-drug raids. His wife and 10 of his supporters were also killed.

Police officers killed Mr Rolando Espinosa, mayor of Albuera town, in the central province of Leyte, in November 2016, shooting him inside a jail cell.

Mr Duterte had tagged Mr Espinosa as one of the biggest drug traffickers in central Philippines.

A week before that, Mr Samsudin Dimaukom, mayor of Saudi Ampatuan town, in Mindanao, and 10 of his men were gunned down in a clash with anti-narcotics officers.

Another mayor in Mr Duterte's drug list, Mr Vicente Loot, a former police general, of Daanbantayan town in central Philippines, survived an ambush in May (2018), four months after Mr Duterte publicly threatened to kill him.

Mr Loot had been repeatedly named by Mr Duterte as among the so-called narco-generals protecting the illegal drug trade.

In an interview with Reuters in 2016, Mr Halili said he backed Mr Duterte's campaign but believed drug kingpins should be the main targets, otherwise thousands of people would be killed.

He expressed concern over the way police conducted the war on drugs and the reliability of their intelligence, and that he might be accused of colluding with narcotics gangs.

"No one is safe - mayors, governors, congressmen - just a false intelligence report by the police can end up with any of them being destroyed," he said in the interview.

"I have a feeling they (police) are going after the small fry to frighten the people," he said.