A strong undersea earthquake of magnitude 7.1 has struck off Taiwan, followed by a powerful aftershock, according to the US Geological Survey.
No damage or injuries were immediately reported, but correspondents says the quake could be felt across the island.
Japan's Meteorological Agency says the danger of a tsunami heading for the Philippines has passed.
The tremors come on the second anniversary of the Asian tsunami, which claimed almost 250,000 lives.
Almost 170,000 died in Aceh in Indonesia with thousands more killed in Thailand, India and Sri Lanka.
Tuesday's first tremor took place at 2026 (1226 GMT) south-west of Hengchun on the southern tip of Taiwan, the island's Central Weather Bureau said - measuring it as 6.7 on the Richter scale.
The second quake happened nearby, about 10 minutes later, and was put at 6.4 on the Richter Scale.
The quake swayed buildings and knocked objects off the shelves in Taipei.
The Pacific Tsunami Warning Centre said no Pacific-wide tsunami was expected.
Earthquakes are frequent in Taiwan, which lies on a seismically active stretch of the Pacific basin.
More than 2,000 people died in a quake seven years ago.