“Police were serving a search warrant when the security guards of the mayor fired at them so our policemen retaliated,” police regional spokesman Superintendent Lemuel Gonda said.

Officers recovered grenades, ammunition and illegal drugs in the raid, according to provincial police chief Jaysen De Guzman.

Duterte won the presidency last year promising to kill tens of thousands of criminals to prevent the Philippines from becoming a narco-state.

Since taking office, police have reported killing nearly 3,200 people in the name of the drug war.

More than 2,000 others have been killed in drug-related crimes, according to police data.

Rights groups say many of those victims have been killed by vigilante death squads linked to the government, and that Duterte may be overseeing a crime against humanity.

In a speech last year, Duterte said Parojinog was among numerous mayors involved in the illegal drug trade.

Police said on Sunday they had conducted surveillance on Parojinog based on the president’s remarks.

“He has many security personnel who carry unlicensed firearms,” regional police chief Timoteo Pacleb said.

Two other mayors that Duterte had also said were on his so-called drug list were killed last year.

In November, Rolando Espinosa, the mayor of Albuera town, was killed during a late-night raid in a provincial jail.

Duterte had defended the officers involved in the raid and ordered their reinstatement, with critics saying the decision would worsen the nation’s “culture of impunity”.

In October, Samsudin Dimaukom, the mayor of the southern town of Saudi Ampatuan, was killed in a shoot-out at a police checkpoint on suspicion that he and his security personnel were transporting illegal drugs, authorities said.