MANILA -- A challenge to Gloria Macapagal Arroyo's leadership by disgruntled marine officers ended without violence yesterday but signaled that efforts to oust the president probably will persist even without widespread popular support.
The five-hour standoff by marines began when their commander was relieved of his duties following what the government said was a foiled coup plot.
It left no doubt that the military has extremely restive elements that are fed up with neglect and corruption, and are susceptible to being drawn in to political adventurism.
Arroyo imposed a state of emergency Friday, saying the coup plot had failed but ''treasonous" elements remained. The president's critics fear the security clampdown is a step toward martial law.
The newest threat to her leadership began earlier yesterday when the head of the marines, Major General Renato Miranda, was removed from his post. The marines are widely rumored to have been among military units involved in the coup plot.
After the announcement of Miranda's removal, marine Colonel Ariel Querubin said he was going to join his commander at their headquarters in suburban Manila. He urged people to defy a ban on rallies and turn out en masse at the camp to protect officers of the elite unit implicated in the foiled plot.
''I'm going to join him at the headquarters and then we'll . . . wait for all the people to really come here and protect us," he said. When asked what they needed protection from, Querubin said: ''Aggression."
But the standoff ended peacefully after only a few thousand supporters heeded his call. Riot police tried to intervene twice to disperse the demonstrators. But the protesters resisted and police backed off each time, apparently on orders not to worsen the situation.
Querubin was named by the military Friday as a key figure in plans by marine officers and their men to walk out and withdraw support for Arroyo. Yesterday he confirmed the plan, saying a majority of the force was ready to go when they found the camp sealed in a security clampdown.
''The junior officers are really raring," he said. ''They're so agitated, so I told them to avoid clashes and shooting, let us just march."
Rumors spread that elite army and other forces were coming to join the restive officers, but they never arrived.
Military spokesman Lieutenant Colonel Tristan Kison played down widespread rumors of unauthorized troop movements and disgruntled troops.
''Let us remain calm, there is no reason to panic," he said.
Kison said Miranda had been asked to be relieved as commander of the marines, citing personal reasons.
He said Miranda has not been implicated in the coup plot. But other reports suggested that he had been forced out.
The 8,000-strong marines are regarded as an elite, well-armed unit at the front line of the government's war against Muslim and communist guerrillas and Al Qaeda-linked militants in the country's volatile south.
The US Embassy said it was monitoring the situation carefully, and it called for a peaceful resolution.
''We reiterate our call for the government of the Philippines and Armed Forces of the Philippines, the Filipino people to respect fully the rule of law, protect civil liberties, human rights and reject violence," embassy spokesman Matthew Lussonhop said.
Miranda was replaced by his deputy, Brigadier General Nelson Aliaga, who took over in a brief ceremony in a military camp.