The death toll from a major earthquake in Taiwan on Wednesday has risen to seven, and the number of injuries has climbed to 736
Officials said the quake was the strongest to shake the island in decades, and warned of more tremors in the days ahead.
Wu said the quake was the strongest since a 7.6-magnitude struck in September 1999, killing around 2,400 people in the deadliest natural disaster in the island's history.
Wednesday's magnitude-7.4 quake struck just before 8:00 am local time (0000 GMT), with the United States Geological Survey (USGS) putting the epicentre 18 kilometres (11 miles) south of Taiwan's Hualien City, at a depth of 34.8 kilometres.
Social media was awash with shared video and images from around the country of buildings swaying as the quake struck.
In Taiwan, Japan and the Philippines, authorities initially issued tsunami warnings but by around 10 am (0200 GMT), the Pacific Tsunami Warning Center said the threat had "largely passed".