MANILA - Philippine President Benigno Aquino will address the nation later Wednesday to try to shore up a Muslim rebel peace deal threatened by a bungled anti-terror raid that killed 44 police commandos.
Public pressure is growing for retribution after Sunday's bloodbath on the southern island of Mindanao, the worst loss of life by the country's police or troops in recent memory.
An autonomy bill now being debated in parliament -- aimed at ending decades of Muslim rebellion in Mindanao which killed tens of thousands -- could be in trouble, analysts and legislators warned.
Senate (upper house) president Franklin Drilon said backing for the measure was seriously eroded when two Aquino allies withdrew support in protest at the killings.
Public hearings on the bill were also suspended as other senators demanded an explanation for the bloodshed.
"My worry is that the Bangsamoro basic law will not be passed because the incident has stoked emotions," Drilon said.
Nearly 400 counter-terrorist policemen were dispatched to a remote farm on Mindanao on Sunday to capture or kill Zulkifli bin Hir alias Marwan, one of the 2002 Bali bombers who has a $5 million price on his head.
After killing a person they thought to be Zulkifli, the police withdrew but were ambushed by the Bangsamoro Islamic Freedom Fighters, a militant splinter group that rejects the peace deal and last year pledged allegiance to Islamic State fighters in Syria and Iraq.
The officers escaped but strayed into territory controlled by the 10,000-member Moro Islamic Liberation Front (MILF), the main rebel group, which signed the pact 10 months ago.
The police suffered 44 dead and 12 wounded. Rebels gave no figures for their own dead or wounded.
Aquino, who will give a live televised address around 6.30 pm (1030 GMT), signed the peace deal in March last year that commits him to pass a Muslim self-rule law -- a key condition for ending the conflict in the south of the mainly Catholic nation.
Ramon Casiple, executive director of the think-tank Institute for Political Reforms, said the autonomy bill now has 11 supporters in the senate, less than half the membership.
The bill needs majority support in both the Senate and the House of Representatives to become law. Parliament had been aiming to pass it by March.
MILF leaders echoed concern over peace prospects. Top leader Murad Ebrahim created a commission to investigate the killings.
'Out for blood'
"Until what happened is established with credibility and integrity, the said incident will weigh down our current efforts to bring peace to our homeland," he said in a statement.
Casiple said the MILF was unlikely to surrender the fighters who clashed with police.
He also said the apparent desecration of the corpses -- with pictures of some of the dead showing missing weapons and clothing -- could spark a desire for revenge among military or police units in the area.
One police survivor said some wounded or captured colleagues had been finished off with shots to the head.
"The military, police, senators are all out for blood. The only thing that will satisfy them is for the perpetrators to be tried in court," Casiple said.
Alumni of the Philippine National Police Academy said they would wear black armbands over 40 days as a sign of mourning.
Julkipli Wadi, dean of the Institute of Islamic Studies at the University of the Philippines, said he expects Aquino to call for calm and try to rally support for the autonomy bill.
"It (the violence) poses a big challenge to the peace process but I think it's not enough reason to stop the peace talks," he told AFP.
"The most serious challenge... is the public anger and I think (the government) is really pressured in terms of how it can call the people to remain calm while asking them to continue to support the peace process."