China on Friday accused Japan of violating the one-China principle under the pretext of disaster relief efforts after a powerful earthquake struck Taiwan's Hualien county.

Foreign Ministry spokesman Geng Shuang made the remarks in response to a question that some senior Japanese officials sent condolences to Taiwan politicians addressing them by their so-called official titles.

"The Japanese side openly attempted to create 'one China, one Taiwan' under the pretext of disaster relief and condolences," Geng said, adding that such a move went against the one-China principle as well as Japan's commitment on the Taiwan issue.

He said China was strongly dissatisfied and had lodged representations to Japan.

"We urge the Japanese side to abide by the principles set out in the four China-Japan political documents, immediately correct its wrong practice, and not make new obstacles for bilateral ties," the spokesman said.

Geng said the Chinese mainland was concerned after the magnitude-6.5 earthquake that hit Taiwan late Tuesday. Zhang Zhijun, head of the Taiwan Affairs Office of the State Council, expressed sincere regards to Taiwan compatriots, and pledged to send rescue teams and offer aid.

As of Friday afternoon, 17 people were confirmed dead in the earthquake, nine from the Chinese mainland, five from Taiwan, two from Canada and one from the Philippines. More than 270 people were injured, according to Taiwan's emergency operation center.

A family of five from the Chinese mainland who were trapped in the rubble of the damaged Yun Men Tusi Ti apartment block were confirmed dead on Friday night. They are believed to be a family－parents, grandparents and a 12-year-old son.

Rescuers continued their search, but were facing great difficulties with very limited space to enter the site, according to Fu Kun-Chi, head of Hualien county.

On Friday, rescuers broke through to a room in the Beauty Inn where a couple－two Canadian citizens originally from Hong Kong－were found, but there were no signs of life.

The hotel, located on the lower floors of the 12-story Yun Men Tusi Ti apartment block, had almost entirely collapsed. The building itself was leaning at a 45-degree angle, forcing crews to stabilize it with steel beams.

It was the most severe earthquake to hit Hualien, a county with a population of about 100,000, in five decades.