The Philippine military insisted Monday it remained loyal to President Benigno Aquino, responding coup rumours that have swirled since a bungled security operation left 44 police commandos dead.

Aquino is facing the biggest crisis of his nearly five years in office over last month's assault in which the special forces killed a top Islamic militant but also unexpectedly came under heavy fire from Muslim rebels.

"If there are officials who are trying to persuade us into joining coup attempts, we will not follow them. They are not part of our chain of command," military public affairs chief Lieutenant Colonel Harold Cabunoc told reporters.

"We have no valid reasons to remove our loyalty from the president of the republic."

The coup rumours began to dominate local media and political chatter last week when a senator told a Senate hearing that unnamed military figures financed by a wealthy individual were plotting to overthrow Aquino.

The military has a long history of meddling in the Philippines' democratic system, including supporting dictator Ferdinand Marcos in the 1970s and 1980s.

With the support of military figures who abandoned Marcos, Aquino's mother Corazon led a "people power" uprising in 1986 that saw the dictator flee into US exile.

She then withstood six coup attempts during the first half of her six years in office.

One of those saw Benigno Aquino shot five times, and he still has a bullet in his neck from the ambush against his mother's forces.

Benigno Aquino's predecessor, Gloria Arroyo, also weathered several coup attempts, although the top military leadership remained loyal to her.

Aquino, who won the 2010 presidential elections in a landslide, has enjoyed widespread popular and military support throughout his time in office.

This had, until last week, ensured there were no coup rumours.

But he has faced public outrage over the January 25 assault against Islamic militant Zulkifli bin Hir on the southern island of Mindanao.

Zulkifli was killed but 44 police commandos also lost their lives after poor co-ordination saw them ambushed by Muslim rebels. At least four civilians and 11 guerrillas died as well.

Still, political and security analysts in the Philippines have said Aquino does not face any serious coup threat as he is still relatively popular and continues to have the support of the military leadership.