MANILA - President Rodrigo Duterte's martial law declaration showed decisiveness but, if mishandled, could also give rise to more Islamic extremists and compromise peace efforts in southern Philippines, a Mindanao-based scholar said Wednesday.

Duterte warned that martial rule in Mindanao would be "harsh" similar to the one declared by the late strongman Ferdinand Marcos Sr. nearly half a century ago.

But Marcos' iron fist rule "fueled the rebellion" in the south, said lawyer Benedicto Bacani, executive director of the Cotobato-based Institute for Autonomy and Governance.

Duterte is now working to address the Mindanao problem by fully implementing separate peace agreements with the Moro Islamic Liberation Front and the Moro National Liberation Front.

"This martial law has to be sensitive to the historical injustice suffered by the Moro people kasi baka mabuksan na naman yung mga sugat na yun," Bacani told ABS-CBN News.

"We have to be careful na hindi nga ito magba-backfire and it will cause more damage than good."

PEACE PROCESS

Duterte placed the entire Mindanao region under martial law following clashes between government troops and the ISIS-inspired Maute terrorist group in Marawi City Tuesday.

Bacani said the president should clarify the scope of his declaration and take into account existing peace efforts, including that with communist rebels.

Giving the military "blanket authority" will also "weaken the system of checks and balances," he said.

"It can hurt the peace process," he said. "Pag ganun, baka masagasaan even those groups that are in a peace process in government."

(It can compromise even those groups that are in a peace process with government.)

Bacani said human rights violations that might be committed under martial rule could be used by terrorists to gain public acceptance and support.

"Sasabihin nila yung military or police or government are no better than us," he said.

(They might say, the military or police or government are no better than us.)

SAFEGUARDS

Bacani said Duterte could not implement a Marcos-style martial rule given existing safeguards in the constitution, which requires the president to report to Congress within 48 hours.

The suspension of the privilege of the writ of habeas corpus should also be done separately, the lawyer noted.

Under the law, any citizen can also question the basis of the martial law proclamation before the Supreme Court.