A 6.8 magnitude earthquake hit the sparsely populated southeastern part of Taiwan on Sunday, the island's weather bureau said, derailing train carriages and causing a convenience store to collapse.

The weather bureau said the epicentre was in Taitung county, and followed a 6.4 magnitude temblor on Saturday evening in the same area, which caused no casualties.

The US Geological Survey measured the quake at a magnitude 7.2 and at a depth of 10 km.

The county government in Hualien, which sits next to Taitung, said two people were trapped in a building housing the convenience store that collapsed in Yuli, while rescue efforts were underway for three people who fell off a damaged bridge.

The Taiwan Railways Administration said three carriages came off the rails at Dongli station in eastern Taiwan after part of the platform canopy collapsed, and the roughly 20 passengers aboard had been evacuated and were uninjured.

The US Pacific Tsunami Warning Center issued a warning for Taiwan after the tremor but later rescinded the alert. Japan's weather agency also lifted an earlier tsunami warning for part of Okinawa prefecture.

The quake could be felt across Taiwan, the weather bureau said. Buildings shook briefly in Taipei.

Science parks in the southern cities of Tainan and Kaohsiung, home to major semiconductor factories, said there was no impact on operations.

More than 100 people were killed in a earthquake in southern Taiwan in 2016, while a 7.3 magnitude tremor killed more than 2,000 people in 1999. (Reuters)