Police, he said, had so far filed 22 cases in connection with the killings, he added.
As for anti-illegal drug operations of the police, de la Rosa said a total of 665 drug suspects were killed by law enforcers during the same period.
Those killed either refused arrest or tried to grab the firearms of the police officers who arrested them, he said.
De la Rosa said that looking at the numbers, vigilantes and drug syndicates were better at killing drug suspects than the police.
The PNP chief however admitted that he found the figures very disturbing.
“We are in charge of the peace and order in the whole Philippine archipelago, and we feel insulted knowing that there are vigilantes doing the killing. It’s like we are ineffective,” the PNP chief added.
The PNP also assured senators it would comply with the law and assign a qualified civilian to head the Internal Affairs Service of the police institution that will probe the killings.