MANILA, Feb. 26 (AP) — A potential threat to President Gloria Macapagal Arroyo's leadership ended peacefully on Sunday night after disgruntled marine officers called off a five-hour standoff that started when their commander was relieved of his duties.

The standoff at marine headquarters showed that efforts to oust Mrs. Arroyo remained alive two days after she imposed a state of emergency, saying a coup plan had been foiled but "treasonous" elements remained. Mrs. Arroyo's critics fear the security clampdown is a step toward martial law.

Earlier on Sunday, the commander of the marines, Maj. Gen. Renato Miranda, was removed from his post. The marines have been widely rumored to have been involved in the coup plot.

After the announcement of General Miranda's removal, Col. Ariel Querubin urged people to defy a ban on rallies and turn out en masse at marine headquarters in suburban Manila to protect the officers implicated in the foiled plot.

But the standoff ended peacefully after only a few thousand supporters heeded his call. Riot police officers tried to intervene twice to disperse the demonstrators. But they resisted, and the police backed off each time, apparently on orders not to worsen the situation with violence.

Colonel Querubin was identified by the military on Friday as a central figure in plans by marine officers and their men to walk out and withdraw support for Mrs. Arroyo. On Sunday, 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, they're so agitated, so I told them to avoid clashes and shooting, let us just march," he said.

The American Embassy said it was monitoring the situation and called for a peaceful resolution.

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