DAVAO, Philippines (AP) -- A powerful earthquake shook the southern Philippines on Tuesday, triggering landslides and loosening boulders that killed six people and injured more than 100 others in a region already damaged by a strong quake two weeks earlier, officials said.
The magnitude 6.6 earthquake was caused by the movement of a fault about 7 kilometers (4.3 miles) deep about 25 kilometers (16 miles) east of Tulunan in Cotabato province, the Philippine Institute of Seismology and Volcanology said.
Tulunan Mayor Reuel Limbungan said about 90% of the houses in three rural villages were damaged by the intense ground movement.
Among the dead were a father and his child who were hit by boulders which rolled down a mountain onto their small farm in hard-hit North Cotabato province. Another child was injured, provincial disaster response officer Mercedita Foronda said. She said more than 100 villagers received injuries, mostly minor, in the province.
Two others died in a landslide and falling debris in Magsaysay town in Davao del Sur province. A pregnant woman was killed by a falling tree in Tulunan and a 66-year-old man died from head injuries after apparently being hit by heavy debris in South Cotabato province's capital, Koronadal, where 30 other people were injured as they dashed out of their homes, offices and shopping malls, police and other officials said.
Several cities and towns suspended classes to allow inspections of school buildings. Several buildings damaged in another quake earlier this month sustained further damage and were closed to the public.
A magnitude 6.3 earthquake on Oct. 16 left at least seven people dead and more than 200 others injured and destroyed or damaged more than 7,000 buildings, officials said.
In July, two earthquakes hours apart struck a group of sparsely populated islands in the Luzon Strait in the northern Philippines, killing eight people.
The Philippines lies in the Pacific "Ring of Fire," an arc of faults around the Pacific Ocean where most of the world's earthquakes occur.
A magnitude 7.7 quake killed nearly 2,000 people in the northern Philippines in 1990.