Manila, June 8 -- People in areas affected by the magnitude 7.8 Sarangani earthquake on Monday should expect aftershocks and stay evacuated until the tsunami warning is lifted, the head of the Philippine Institute of Volcanology and Seismology (Phivolcs) said.

"People should stay away from damaged buildings, and check for cracks," Phivolcs Director Teresito Bacolcol told the Philippine News Agency in an interview.

He also advised the public to follow the instructions of local disaster risk reduction and management offices.

The earthquake, which was generated by the Cotabato Trench, has affected many areas in Mindanao.

Phivolcs earlier issued a tsunami warning and advised residents of coastal areas in Sarangani, Davao Occidental, Tawi...