MANILA (Reuters) - The Philippines hit back at a prominent U.S.-based human rights group on Monday for what it said was a misleading death toll of more than 12,000 in its war of drugs, putting the number at half of that and championing its rate of arrests and drug seizures.

New York-based Human Rights Watch on Thursday said President Rodrigo Duterte had not only resisted calls to end his brutal campaign, but handled criticism by “impugning, harassing, and threatening critics of the government and human rights defenders”.

The president’s office held a news conference on Monday with police and the drugs enforcement agency to present a detailed rebuttal to a report the foreign minister, Alan Peter Cayetano, said was without “any real research, study or investigation”.

Cayetano at the weekend challenged HRW to prove 12,000 people had died in the drugs war, while police spokesman Dionardo Carlos asked the group to provide evidence to help with investigations.

“We hope that they will be more specific, engage us so we can help look into the cases,” he said.

Carlos said 3,987 people had been killed in anti-drug operations during the 18-month crackdown, while some 11 percent, or 2,235, of the total 19,560 murders under police investigation were drug-related.

Eighty-five security forces had been killed during the campaign, he said.

In response to international criticism over what activists and the political opposition say are summary executions and cover-ups, Duterte suspended police from the campaign in October, but has since decided to bring them back.

The authorities deny systematic abuses are taking place in the campaign and say those killed had violently resisted arrest. Activists dismiss that as implausible.

“Oplan Tokhang”, where police visit homes of users and dealers and seek their surrender, is to resume soon, Carlos said, adding that it had brought positive results.

He said more than 1.3 million drugs users had turned themselves in seeking rehabilitation and police had made 119,361 arrests.

The authorities have seized more than two and a half tonnes of the methamphetamine “shabu”, with a street value of 13.2 billion pesos ($259.4 million)

($1 = 51 pesos)