MANILA — Residents of the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM) did not expect the flash floods spawned by severe tropical storm Paeng, which left dozens dead in the region, an official said on Monday.

The BARMM is rarely hit by the 20 or so cyclones that strike the Philippines yearly and flooding only usually happens around the Ligawasan Marsh, a catch basin for rainwater from Bukidnon, Cotabato provinces and Sultan Kudarat, said Bangsamoro civil defense chief Naguib Sinarimbo.

But the region started experiencing heavy rains on Friday, while Paeng was still approaching Luzon, the official told ANC's "Rundown."

"The water from the mountain ranges in Upi, Datu Blah and Datu Odin Sinsuat rushed down to communities, mixed with landslides," Sinarimbo said.

"The flashflood and the landslide is a new phenomenon in the region, probably part of the climate change that we are now experiencing. As a result of that, our people is not used to preparing for flashfloods and landslides. We are used to the preparations for gradual rise of water around the Ligawasan Marsh," he added.

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The nationwide death toll from Paeng has jumped to 98, the disaster agency said on Monday.

In the Bangsamoro, Paeng affected some 582,000 residents and left 53 people dead, mostly in 4 towns in Maguindanao del Norte, said Sinarimbo.

He said Bangsamoro authorities suspended rescue efforts on Sunday and focused on retrieval operations in Maguindanao del Norte's Kusiong village, which was buried by a massive landslide that created a huge mound of debris just below several mountain peaks.

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Landslides and flash floods originating from largely deforested mountainsides have been among the deadliest hazards posed by storms in the Philippines in recent years.

Scientists have warned that deadly and destructive storms are becoming more powerful as the world gets warmer because of climate change.

State weather forecaster PAGASA warned that another tropical storm, Queenie, would bring more rains as Paeng moved away.

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— With a report from Agence France-Presse