Reynaldo Parojinog was the third mayor to be killed in President Rodrigo Duterte's crackdown on the narcotics trade.
A mayor from southern Philippines was killed during a pre-dawn raid at his home on Mindanao island, police said on Sunday.
Reynaldo Parojinog was the third mayor to be killed in the government's bloody narcotics crackdown.
The mayor was on President Rodrigo Duterte's list of top drug suspects.
Parojinog, the mayor of Ozamiz city, was killed along with his wife, his brother and nine others in what police described as a dawn raid on his home.
"Police were serving a search warrant when the security guards of the mayor fired at them, so our policemen retaliated," regional spokesman Superintendent Lemuel Gonda said.
However Jeffrey Ocang, an aide to the Parojinogs who are an influential political clan, denied there had been any exchange of gunfire and said the mayor's camp did not fire a shot.
Police said none of their officers were hurt apart from one who sustained a minor injury from an explosion.
Following the raid police arrested Parojinog's daughter, the city's vice-mayor, and said she would face charges.
Duterte won the presidency last year after promising to kill tens of thousands of criminals to prevent the Philippines from becoming a narco-state.
Since he took office, police have reportedly killed nearly 3,200 people in the drug war.
More than 2,000 other people 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 mayors involved in the illegal drug trade.
Two other mayors Duterte mentioned in his so-called "drug list" were killed last year.
In November, Rolando Espinosa, the mayor of Albuera town, was killed inside his cell during a night-time raid in a provincial jail.
Police claimed Espinosa shot at them first despite being in custody.
Duterte defended the officers involved in that raid and ordered their reinstatement, but critics said 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 shootout at a police checkpoint on suspicion he and his security personnel were transporting illegal drugs, authorities said.