TAIPEI -A strong earthquake struck southeastern Taiwan, bringing at least three buildings down in a small town and tearing up roads -- but forecasters said the threat of a regional tsunami had passed. The quake hit at 2:44 pm (0644 GMT) about 50 kilometres (30 miles) north of the city of Taitung at a depth of 10 kilometres, the United States Geological Survey said. Its initial strength was given as magnitude 7.2 but the USGS later downgraded it to 6.9. Multiple aftershocks were also recorded. Japan’s Meteorological Agency and the Pacific Tsunami Warning Center issued tsunami advisories shortly after the quake, but both later said there was no longer a threat of high waves. In the Taiwanese town of Yuli, a two-storey building that had a 7-Eleven convenience store on the ground floor collapsed. Video footage posted by Taiwan’s Central News Agency showed panicked residents running towards the building, which sent up a thick cloud of dust as it caved in. The Hualien fire department said four people who were trapped in the building were rescued. Two other buildings in the town collapsed but no one was inside them, the department added. Two nearby bridges collapsed while two others were damaged.  The Taiwan Railways Administration (TRA) said a train derailed at Dongli station in Hualien after it was hit by concrete from an overhead canopy that came loose during the quake.