The Philippines has made progress against corruption in political life but more work is needed to keep the momentum going, President Benigno Aquino said.

"Clearly, our reforms have won us momentum," Aquino said in a speech to the International Conference on Public Administration and Governance held in Manila.

"And it is up to all of us, whether in the private or public sector, to maintain this momentum. The problem of poverty is one that must be solved, there are still corrupt officials who will be prosecuted and jailed," he said.

But Aquino emphasized efforts to stamp out corruption can't be left to a single political office, a report by The Manila Times said.

"We have to do it together," said Aquino.

The imprisonment of former president, and now the representative for Pampanga province, Gloria Arroyo and former Commission on Elections Chairman Benjamin Abalos Sr. shows the country has "already begun to move toward a larger realm of possibility," he said.

"Only a few years ago, we had been hopelessly caught in a spiral of apathy and paralysis. We had become used to scandals of graft and corruption that faded away with no one held to account," Aquino said.

The first official to be impeached in the country was former President Joseph Estrada, in November 2000, GMA News reported in January.

Estrada's impeachment trial at the Senate was cut short by a popular uprising in January 2001 that deposed Estrada and catapulted Arroyo, then the vice president Arroyo, to the presidency, GMA reported.

Chief Justice Renato Corona was impeached in December for alleged betrayal of public trust, culpable violation of the Constitution, graft and corruption.

Aquino praised the National College of Public Administration and Governance for producing officials whom he said "will help him nurture institutions in government and in civil society."

Part of the solution to the corruption problem is to ensure a country's population isn't afraid to vote in what must be free and fair elections.

Often it is the poor people who are intimidated by the rich and powerful, he said.

He also said that is why the federal government has handed over more than $202 million to the Autonomous Region in Muslim Mindanao, the country's restive southern area, to show the government's sincerity in helping Muslims as they prepare for the elections next year.

"Likewise, this explains why we have been consistent in holding peace talks with rebel groups, because, as we have learned from what is going on in the world, progress is impossible if a nation stands divided," Aquino said.

In Mindanao and surrounding areas local politics remains mired in deadly clan feuds and uneasy alliances.

A sixth potential witness in one of the country's worst massacres was killed earlier this year, public prosecutor Nena Santos said last month.

Alijol Ampatuan was the victim of a drive-by shooting, a report by the BBC said.

He was related to the powerful Ampatuan clan, accused of the 2009 killings know as the Maguindanao massacre, also called the Ampatuan massacre after the town where police found mass graves shortly after the daylight slaughter Nov. 23, 2009.

The killing happened in the town of Ampatuan in Maguindanao province, on the island of Mindanao.

Andal Ampatuan Jr and five other members of the Ampatuan family, including patriarch Andal Ampatuan Sr., are among 196 people facing charges related to the killings.

Among the dead are many female members of a rival political family, the Mangudadatus, as well as 30 reporters travelling with them as the group headed off to file candidacy papers for a provincial election.