MANILA -- A powerful earthquake struck near the Philippine city of Davao on Sunday, damaging buildings and causing several injuries, officials said, the latest in a series of tremors to strike the southern part of the country in recent months.

The magnitude 6.8 quake was centered 61 km (38 miles) southwest of Davao on the island of Mindanao, at a depth of 28.2 km, the U.S. Geological Survey said, revising down the magnitude from an earlier 6.9.

The Pacific Tsunami Warning Center said there was no tsunami threat from the quake, based on available data.

Anthony Allada, public information officer of Magsaysay Town in Davao del Sur province, near the epicenter, said 14 people were injured but none seriously. Roads and buildings, including the local government office, were damaged and power was out in the town, he said.

The region was shaken by four powerful quakes in October and November, which together killed at least 20 people.

“We don’t know what to do anymore. Do we respond first or attend to our families first?”, Allada told DZMM radio.

President Rodrigo Duterte, who is from Davao, was in the city when the quake struck.

“He is ok. He and his daughter Kitty were in their house when the quake struck,” presidential spokesman Salvador Panelo said. “First Lady Honeylet was on her way home when the ground trembled. She said her car was swaying. She is unhurt.”

The Philippine Institute of Volcanology and Seismology (Phivolcs) said damage and aftershocks could be expected.

Several strong aftershocks were recorded after the main tremor, the strongest a magnitude 5.7 centered north of General Santos City.

Radio DZMM reported power was out in General Santos City, where patients at a local hospital were being evacuated.

Video footage of the latest quake posted by users on Twitter showed overhead electrical wires swaying and erupting in a shower of sparks. Another video showed water sloshing out of a hotel swimming pool.

One picture said to be from Padada, in Davao del Sur, showed a building collapsed onto a car. Reuters could not immediately verify the pictures but the local disaster agency reported one three-story building had collapsed. There was no information if any people were inside or under the building.

The Philippines sits on the geologically active Pacific “Ring of Fire” and experiences frequent tremors.