Philippine government forces would remain vigilant despite the reported death of ISIS leader Abu Bakr al-Baghdadi, Malacanang said on Monday.

In a press briefing, Presidential Spokesperson Salvador Panelo said the death of the terrorist leader was a good news.

However, he said, "the leader of one group does not mean the extinction of that band of terrorists, we know that for a fact."

Panelo cited the case of Osama bin Laden, slain leader of terrorist al-Qaida. He said that despite Bin Laden's death, terrorism still exists.

He said that Baghdadi's death could also discourage his followers.

"But as far as we are concerned, whether the leader dies or not, we will secure that part of our country from them," he said, referring to Mindanao.

President Rodrigo Duterte earlier acknowledged the presence of ISIS in southern Philippines, which has been placed under martial law following the Marawi siege.

US President Donald Trump announced on Sunday that Baghdadi, the "world's number one terrorist leader," was dead. Celerina Monte/DMS