MANILA, Philippines (AP) _ President Corazon Aquino refused today, the birthday of her ousted predecessor, Ferdinand Marcos, to allow his remains to be buried in the Philippines.

Meanwhile, a bomb exploded at a parking lot inside the suburban Philippine army headquarters, but no one was injured, army spokesman Col. Benjamin Enrile said.

There were no suspects, he said. It was the 20th explosion in the capital since Aug. 13. Police believe most bombings were carried out by right-wing extremists.

About 1,000 of Marcos' supporters marked his 73rd birthday by marching through through Manila's streets.

Marcos' widow, Imelda, appealed to Mrs. Aquino on Monday to allow her to bring home her husband's remains from Hawaii. Marcos died there last Sept. 28.

''(The return of Marcos) has to await a more propitious time,'' Mrs. Aquino said in a statement read by Press Secretary Tomas Gomez. ''Prudence dictates that additional occasions for debilitating and distracting activities be avoided.''

Marcos was ousted in February 1986 and driven into exile by a popular revolution. Mrs. Aquino consistently refused to let him return, citing security concerns, and she continues to bar Mrs. Marcos from the Philippines.

After a Roman Catholic Mass today for Marcos, House of Representatives minority leader Rodolfo Albano read a statement praising the achievements of the former leader.

Albano said Marcos was a ''good man judged at a wrong time by the wrong minds,'' apparently referring to Mrs. Aquino's government.

''Everyone has human faults, for who has none?'' the statement added. ''It is said that when a man is gone, only his misdeeds are often remembered, no matter how few, forgetting all his good deeds.''

The statement also appeared as a full-page advertisement in several Manila newspapers.

Among those who attended the Mass were some former members of Marcos' Cabinet, several congressmen and retired generals.

Mrs. Marcos said Monday in Honolulu that she was would do ''everything to support'' Mrs. Aquino and begged her to reconsider her ban.

Mrs. Aquino replied: ''Sincerity is subject to proof.''

She said she would make no deals with Mrs. Marcos until the former first lady returns money allegedly taken from the Philippines. The Aquino government has accused the Marcoses of stealing up to $10 billion during 20 years in power.

The Marcoses face 35 civil suits in the Philippines. Mrs. Marcos was acquitted in the United States of racketeering charges. Marcos died before he could be arraigned.