MANILA - The Armed Forces of the Philippines was saddened by the death of Cayamora Maute, father of extremist leaders who occupied parts of Marawi City, the chief of staff said Monday.

"Ikinalulungkot natin yung pagkamatay niya kasi marami pa sana siyang sasagutin sa justice dahil maraming biktima ng karahasan na dulot ng terorismo sa Marawi," AFP chief of staff General Eduardo Año told ABS-CBN News at the sidelines of the National Heroes' Day celebration.

(We are saddened by his death because he is answerable to justice because there were many victims of terrorism in Marawi.)

"Nalulungkot din ang kaniyang pamilya, pero ganiyan talaga, may sakit naman siya eh. Talagang time na niya siguro," he added.

(His family must have also been sad, but that's how it is. He was sick. Maybe it was already his time.)

Cayamora, 67, died on Sunday after he was rushed to the Taguig-Pateros Hospital. The cause of his death has yet to be announced, as of writing.

The Maute patriarch was arrested in Sirawan, Toril, Davao City in June. He was transferred to Camp Bagong Diwa in Taguig in the same month.

His sons, Omar and Abdullah, who are said to have been radicalized while studying abroad, had led extremists in attacking Marawi City last May 23, prompting President Rodrigo Duterte to declare martial law in Mindanao.

• READ: Engineer-turned-terror suspect? Meet the Maute patriarch

As of Thursday last week, the fighting, which has been going on for four months, has killed 45 civilians, 129 state troopers, and 595 enemies.