President Corazon Aquino pledged Saturday to unite the nation and begin "the ways of peace" as Filipinos marked the third anniversary of the popular uprising that brought her to power and toppled Ferdinand Marcos.

Several prominent Filipinos boycotted the celebrations because of disappointment with Aquino. Police opened fire to drive off about 3,000 Marcos supporters demanding their leader's return from Hawaiian exile.The military arrested three suspected right-wing extremists in a van filled with 30 cases of explosives outside the capital.

Aquino, who returned Saturday from the funeral of Japan's Emperor Hirohito, said President Bush and other international leaders "told me that they admire us Filipinos for that non-violent revolution."

She made her comments following a Roman Catholic Mass along Epifanio delos Santos Avenue, where hundreds of thousands of civilians turned out three years ago to protect soldiers who mutinied against Marcos.

Police estimated Saturday's crowd at 30,000, smaller than the last two anniversaries.

"I think it is up to the leaders of your country to initiate the ways of peace," Aquino told the crowd. "I hope you will be patient with us because we are in a transition period. I promise that this day, we will unite and do a better job in serving you."

Cardinal Jaime L. Sin said before Aquino's speech that corruption and political bickering were diverting attention from eradicating poverty and social injustice.

"The old politics have come back to the dismay of us all - positioning for power, the corruption, the grandstanding, the influence-peddling, the petty bickering," he said.

Shooting erupted at a separate rally in Manila by about 3,000 Marcos loyalists, who demanded Marcos be allowed to return from Honolulu, where he has been exiled since his 20-year rule ended Feb. 25, 1986.

Witnesses said three plainclothed policemen bolted from a vehicle and forced one Marcos supporter inside. When protesters rushed the car, the policemen fired in the air and sped away, the witnesses said.

Police spokesman Albert Gatos said he and two fellow officers were transporting a robbery suspect when the loyalists attacked their car. Gatos said one loyalist was arrested.

Saturday's celebrations began with the ringing of church bells across this island nation and included fireworks, street dancing and unveiling of a giant statue of the Virgin Mary.

Among those boycotting the celebrations was Sen. Juan Ponce Enrile, the former defense minister who led the military mutiny against Marcos but then turned against Mrs. Aquino as well.

"They really wanted change for the country," said Enrile, who was fired as defense minister in November 1986 after a coup attempt by his followers. "Our future is still dim."