MANILA - The series of quakes that shook Mindanao in October caused over P1 billion in damage in Davao del Sur, a local official said Friday.

Disaster officer Christopher Tan said damaged buildings in Davao del Sur grew in number, especially after a 6.5-magnitude tremor struck nearby Tulanan town in Cotabato on Thursday.

• Magnitude 6.5 temblor rocks Cotabato days after powerful quake

Tulunan was also the epicenter of the devastating 6.3-magnitude quake on Oct. 16 and the 6.6-magnitude temblor that struck on Oct. 29.

• Cotabato quake death toll rises to 7

Due to the earthquakes that hit Mindanao, Davao del Sur's economy is facing a crisis.

Magsaysay town and Digos City in the province have been placed under a state of calamity.

Officials said that their calamity funds, which would become accessible with the state of calamity declaration, are not enough to support and assist families whose houses were destroyed by the temblors.

In Digos, 8 malls and grocery stores shut down due to cracks the quakes caused. Hagonoy town officials, meanwhile, gave water containers to affected residents after the area's water system was destroyed by the temblors.

The Digos local government pleaded for aid from the national government, saying they need tents, blankets, and mattresses for evacuees.

• 'Blind faults'? Phivolcs explains series of strong quakes in Mindanao

- Report from Vina Araneta-Pilapil, ABS-CBN News