President Rodrigo Duterte said on Tuesday that Peace Adviser Jesus Dureza has resigned as he dismissed two other executives of the Office of the Presidential Adviser on the Peace Process ( OPAPP).

In a speech in Bohol, Duterte said he would still fire another undersecretary.

"I'm very sad that I accepted the resignation of Secretary Dureza and I fired his Usec. Ronald Flores OPAPP, which is the presidential office for the peace process, and a Director Yesthon Donn Bacay. I'm still going to fire another one. I'll not talk about it anymore," he said during the inauguration of the Japanese-funded airport in Panglao Island.

Duterte did not say why he fired Flores and Bacay.

"Well in fairness to Secretary Dureza, he did not have, maybe because he's the head of office" he added.

He said the undersecretary whom he would fire could be a "loose canon that's why the government finds difficulty."

In his resignation letter, Dureza said the two officials were terminated "due to corruption."

"I am sad because despite my efforts to be compliant with your strong advocacy against corruption, I failed," he said.

"I truly am sad that OPAPP, as an institution which I head, had to suffer publicly due to the acts of a few.

Nonetheless, I take full responsibility and apologize for all this," Dureza said.

He said he tendered his resignation "to pave the way for the needed reorganization that Your Excellency may wish to undertake at OPAPP."

He justified that he took effort to prevent corruption in his office, such as installing an internal Ombudsman with an outside lawyer to help validate and gather evidence due to persistent rumors about corruption.

"I even took efforts to publicly warn the public through the social and mainstream media against corruption in the implementation of PAMANA ( national government programs and framework for peace and development) projects and requested information with assurances of confidentially of the source," he added.

Dureza said he had left the internal functions to his other OPAPP appropriate officials while he concentrated on the big task of dealing with challenges of peace.

Last week, Duterte fired Housing Urban Development Coordinating Council Secretary-General Falconi Millar following complaint that he allegedly tried to extort money from a company involved in one of the agency's projects.

Millar, however, claimed that he was a victim of a demolition job. Celerina Monte/DMS