MANILA, SEPT. 21 -- President Corazon Aquino today appointed a top general to head a special task force to track down the leader of last month's aborted coup.

Col. Gregorio (Gringo) Honasan, who led the Aug. 28 mutiny, remains at large. He has given numerous press interviews, becoming the country's most sought-after media celebrity, but has eluded police capture. Some political analysts have suggested that military authorities are reluctant to arrest Honasan because of widespread sympathy in the armed forces for grievances aired by Honasan.

Aquino named Brig. Gen. Ramon Montano to head the task force, in what one high-ranking military official said amounted to a virtual vote of no confidence in Gen. Fidel Ramos, the armed forces chief of staff.

The appointment came as about 5,000 demonstrators marched peacefully through the capital to protest the slaying Saturday of a prominent leftist leader, Leandro Alejandro, and to mark the 15th anniversary of the declaration of martial law by ousted president Ferdinand Marcos.

The military instability, increased attacks by communist guerrillas and labor unrest have fueled speculation in the press and in political circles that Aquino eventually may be forced to impose martial law or a lesser state of emergency.

Marcos declared martial law in 1972 during a rising crime wave, labor unrest and a sense of anarchy in Manila's streets. Many political analysts, officials and opposition leaders -- including Aquino's own defense secretary -- have been quoted in recent weeks as warning that the situation now is as serious as it was 15 years ago, and even more confusing.

At an emergency meeting with her top military and law enforcement officials today, Aquino castigated the military for being unable to solve a string of murders, including the August slaying of a powerful Cabinet member, and for being unable to locate Honasan, according to one participant. Most pro-Aquino and opposition political leaders said they opposed the imposition of martial law or a state of emergency, although few would rule it out if the situation continues to deteriorate.

"You cannot arrest the problem by simply instituting authoritarian rule," said opposition Sen. Juan Ponce Enrile, who administered martial law as Marcos' defense minister. "That is the experience that we had in the past. What is important is for us to enforce the law."

But most political analysts also said that Aquino is unlikely to declare a state of emergency because of the personal experience of the jailing of her late husband, the former senator Benigno S. Aquino, Jr., during martial law under Marcos. Moreover, they said, emergency rule would increase the power of a military that the president does not fully control now.

Presidential aides told reporters that Aquino had no plans to declare martial law or a state of emergency. "The normal facilities of government are capable of handling the situation," said Defense Secretary Rafael Ileto.

Officials say they have no suspects and few leads in the slaying of Alejandro. Leftists have blamed right-wing elements in the military.

Many of the country's other prominent leftist leaders are expected to go underground following the slaying, and some analysts expected the political landscape to become more polarized.