North Korean leader Kim Jong-il's son and heir-apparent Kim Jong-un is reportedly in China. A high-ranking South Korean government official said Kim Jong-un, accompanied by his uncle Jang Song-taek, the vice chairman of the National Defense Commission, crossed the border to meet top Chinese leaders.

Kim junior apparently arrived in Tumen, eastern Jilin Province in China early Friday morning. Bridges and nearby areas have been heavily guarded by police since Thursday.

The trip comes eight months after Kim junior was named to the central committee of the Workers Party and appointed vice-chairman of the party's powerful central military commission. He is expected to seek assurances of Chinese support for his succession to the leadership and consolidate his status.