A magnitude 7.8 earthquake has shaken part of the southern Philippines, and a tsunami was possible on some regional coasts. Power outages were reported and people were urged to go to higher ground. No further information on damage or casualties was immediately available. The Philippine Institute of Volcanology and Seismology said the epicenter was 8 miles from General Santos city on the island of Mindanao. It was just 6 miles deep and struck at 7:37 a.m. Monday. The Pacific Tsunami Warning Center said tsunami waves up to 10 feet were possible on some coasts of the Philippines. Waves up to 3 feet were possible in parts of Indonesia.