A North Korean diplomat based in Ethiopia defected to Seoul in August after seeking asylum at the South Korean Embassy in the African country, multiple sources said Friday.

The North Korean man, whose identity is unknown, stormed into the South Korean embassy in Addis Ababa, asking for help for his defection to the South, they said.

"At that time, he worked for the North Korean office of the trade representative in Ethiopia ... I've learned that he is not a senior official, though," one source said without elaborating further. 

The North Korean Embassy later learned of the defection and strongly protested, the source said, adding that details of the man's defection, including his motive, have not been known, .

South Korea's foreign ministry refused to confirm the defection.

Each year, hundreds of North Koreans defect to South Korea via China and other countries. Currently, South Korea is home to more than 25,000 North Korean escapees.

Defections by North Korean diplomats are not uncommon. In 2010, a North Korean embassy official in Ethiopia defected to South Korea. (Yonhap News)