Philippine anti-narcotics officers gunned down a town mayor and nine of his men in a clash in one of the bloodiest operations since President Rodrigo Duterte launched a crackdown on illegal drugs.

Samsudin Dimaukom, mayor of the southern town of Saudi Ampatuan, was one of more than 150 local government officials, judges and police identified by Duterte earlier this year as being involved in the illegal drug trade.

He ordered them to surrender immediately or be hunted down.

The mayor had turned himself in to police but denied he was involved in the illegal drug trade. He had told the media that he was fighting illegal drugs himself and supported Duterte's crackdown. 

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Ahead of the shootout on Friday, police received information that Dimaukom's group was planning to transport a "huge" amount of methamphetamine from Davao city, Duterte's hometown, to Maguindanao province, where Saudi Ampatuan is located.

Police spokesman Superintendent Romeo Galgo said Dimaukom and his security personnel opened fire after anti-narcotics police stopped their vehicles at a checkpoint on suspicion they were transporting illegal drugs.

Officers returned fire, killing the men in the town of Makilala, about 950 kilometres south of the capital Manila.

"Suspects [were] heavily armed and fired upon the law enforcers, which prompted them to fire back," Galgo said.

Al Jazeera's Rob McBride, reporting from Manila, said no drugs were found when Dimaukom's compound was searched at an earlier date. 

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"After he and his wife turned themselves to the police, their compound was searched and no drugs were found," he said.

Dimaukom has been previously named by Duterte of involvement in illegal drugs [YouTube]

"But significantly at that time, because he was suspected and on the list, his official police and military security detail were taken away."

Duterte's deadly crime war has claimed more than 3,800 lives and drawn criticism from the US, the UN and international rights groups who have accused police of summarily executing suspects.

Duterte, who swept to power in May elections on a pledge to eradicate drugs, has described his critics as "fools" and said he is not breaking any domestic laws by threatening to kill criminals.

After returning from a trip to Japan late Thursday, he threatened to step up police killings of drug suspects.

In September, the EU called on the Philippine government to put an end to the killings of drug suspects.

Duterte replied by unleashing a series of expletives against the bloc.

"I have read the condemnation of the European Union. I'm telling them, 'F**k you,'" Duterte said in a mix of Tagalog and English, before describing the EU as hypocrites trying to "atone" for guilt over its members occupying other countries in the past. 

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Source: Al Jazeera News And News Agencies