SEOUL (Kyodo) An aide to Kim Jong Un, the third and youngest son of North Korean leader Kim Jong Il, planned to assassinate Kim Jong Nam, the eldest son of Kim Jong Il, KBS television reported Monday.

The plan was foiled by Chinese authorities, KBS said, citing a Chinese government source.

The plan envisaged Kim Jong Un's aide eliminating a person in North Korea close to Kim Jong Nam before killing Kim Jong Nam in Macau, KBS said.

Chinese authorities detected the plan early last week and issued a warning to North Korea, according to KBS.

Kim Jong Nam is now under Chinese protection, it said.

Kim Jong Il was not informed while the assassination plan was being devised, KBS said.

South Korea's Yonhap news agency reported earlier this month that Kim Jong Il designated Kim Jong Un as his successor shortly after North Korea conducted its second nuclear test May 25.