The earthquake that hit Taiwan's east on Wednesday morning was "the strongest in 25 years", said the director of Taipei's Seismology Centre.

"The earthquake is close to land and it's shallow. It's felt all over Taiwan and offshore islands... it's the strongest in 25 years since the (1999) earthquake," Wu Chien-fu told reporters, referring to a September 1999 quake with 7.6-magnitude that killed 2,400 people.