China's President Xi Jinping has expressed his condolences over the earthquakes that hit southern Japan to Japanese emperor Akihito, Xinhua news agency reported late on Monday (April 18).

"On behalf of the Chinese government and people, I would like to express our deepest condolences to the victims, and our sincere concern for the families of the deceased and the injured," Mr Xi said in his message according to Xinhua.

"I hope the Japanese people can overcome the difficulties as soon as possible and rebuild their homes."

Mr Xi was granted an audience with Akihito in 2009 when he visited Japan as China's Vice-President.

Relations between the two countries have since deteriorated after nationalist Prime Minister Shinzo Abe came to power in Japan.

At least 42 people were killed and more than 1,000 others injured after two strong earthquakes rocked Kumamoto in southern Japan's Kyushu island last week.