MAYNILA - At least 156 barangays in 24 towns and a city in Cagayan province are swamped with floodwaters due to heavy rains brought by Typhoon Ulysses and the northeastern monsoon.

In an interview with ABS-CBN's TeleRadyo on Friday night, Cagayan Gov. Manuel Mamba said this is the worst flooding in the province since he became its chief executive.

According to the governor, water from Ulysses' heavy rains in nearby provinces like Isabela, Nueva Vizcaya, Quirino, Ifugao, Kalinga flowed to Cagayan, resulting in a deluge.

"Kami po 'yung catch basin ng Cagayan River. Ang Cagayan River extends to Nueva Vizcaya. Lahat po ng tubig ng nandiyan, bumababa po dito sa'min.

Due to the heavy downpour, the Magat dam in the region had to release excess water after it reached critical level. Mamba noted this "exacerbated" flooding in Cagayan.

"Kaya ngayon po napakataas ng level ng Cagayan River," he said.

Rescue operations in Cagayan are ongoing, Mamba said, adding that rescue boats are needed in the province.