NUMBERS SPEAK. The government's crackdown on illegal drugs and criminality has pulled down crime rates nationwide, the Philippine National Police (PNP) claimed Tuesday.

At a Senate inquiry on drug-related killings, Philippine National Police chief, Director Ronald "Bato" dela Rosa said index crimes nationwide went down by 31 percent -- from 17,105 incidents in July 2015 to 11,800 in July this year.

The PNP defines index crimes as crimes against persons (rape, murder, homicide, etc.) and crimes against property (robbery, theft, etc.).

Dela Rosa said rape cases saw the most significant decrease at 49 percent.

He said the nationwide daily average of focused crimes also slid by 49 percent, from 499 incidents in the second semester of 2015 to 256 cases during the same period this year.

The generally improving crime situation, he said, is also reflected by daily crime trends which which reached a peak of 353 cases on July 4, but dipped to 23 incidents on August 21.

The drop in crime rates coincides with an increase in the surrender and arrest of drug suspects.

Dela Rosa said 673, 978 drug-tainted individuals have surrendered to authorities from July 1 to August 22.

During the same period, 11, 784 drug suspects were arrested while 756 were killed in police operations

"The PNP is now more aggressive in the campaign against drugs. It is because the PNP believes we have a President who is willing to support us all throughout this campaign," he said.

President Duterte has declared a bloody war against drug lords and suspected criminals in order to achieve his campaign promise of suppressing crime and narcotics within his first six months in office.

Human rights advocates are however alarmed over how the anti-drug drive may be encouraging police abuses and summary executions.

The PNP is currently investigating 1,067 unexplained killings, which dela Rosa said, were not all drug-related.

Watch a live streaming of the hearing here.