MANILA - Defense Secretary Delfin Lorenzana on Wednesday admitted that the military failed to properly appreciate intelligence reports about movements of the Maute group in Lanao del Sur.

This following clashes between government troops and members of the terror group on Tuesday, which prompted President Rodrigo Duterte to declare martial law over the entire Mindanao.

"Ang hindi namalayan nakapasok sila sa Marawi kasi sa mga bundok natin sila binubugbog," Lorenzana told reporters after he arrived from Moscow.

"The intelligence is there, but the appreciation of the intelligence was not complete, hindi nila na-process masyado," he said.

Lorenzana said Maute members were "able to elude the military's intelligence capabilities" when they supposedly brought leader Isnilon Hapilon to Marawi City for medical treatment.

He said the Marawi clash was the tipping point for President Duterte, who has been mulling the declaration of martial law since November last year.

"This is the tipping point, na nandiyan na sila nagpaparada-parada sila, sila nakarating sa amin yung pictures sinusunog nila ang buildings doon and parading and raising the flag," Lorenzana said.

The official described the difficulty of apprehending members of the Maute group in Marawi because they have relatives in the area who may be helping them hide.

"...[N]gayon ang problema dito they have a lot of relatives in Marawi City gaya ng nangyari sa countryside, maraming NPA (New People's Army) [rebels] dyan, kapag pumupunta tayo wala tayong makita dahil tinatago ng komunidad," he said.

Lorenzana also echoed President Duterte's view that martial law will help solve drugs, terrorism and other security problems in Mindanao.