North Korean leader Kim Jong Il traveled Friday by train through northeastern China, marking his third trip to the country in roughly a year, South Korea’s Yonhap news agency said.

The conspicuous armored train entered China’s Jilin province, on the border of North Korea, raising speculation from analysts about the final destination -- and the makeup of the full traveling party.

The latest South Korean media reports suggested that Kim Jong Il was making the trip without his youngest son and presumed successor, Kim Jong Eun. That account contradicts widespread reports earlier in the day that Kim Jong Eun was making the trip on his own--- presumably to receive an endorsement from leaders in Beijing.

One South Korean government official, speaking Friday night, said that Seoul had not yet determined which Kims were aboard the train. Such North Korean state visits to China are shrouded in secrecy, with Chinese foreign ministry officials acknowledging the trips only after they conclude.

North Korea’s state-controlled media reported nothing Friday about a visit, which is not unusual for the reclusive regime.

But such trips draw high-profile attention from Japanese and South Korean media, which flood likely train routes with cameramen in hopes of grabbing footage of the rarely seen North Korean leader.

In the midst of a presumed hereditary succession, Pyongyang so far has anointed Kim Jong Eun with top party and military positions. But the younger Kim has yet to make a foreign visit since being tapped last September as the third-generation leader from the Kim family.

Kim Jong Il traveled twice last year to China, most recently last August -- when he visited several sites where his father, North Korean founder Kim Il Sung, spent his formative years.

“It is unusual for Kim Jong Il to go to China so soon after his last visit,” said Cheong Seong-chang, a Seoul-based North Korea analyst at the Sejong Institute. “But it is a sign showing the interrelations between North Korea and China are getting closer.”

The analyst suggested that Kim Jong Il could be visiting China to discuss international pressure being placed on Pyongyang for denuclearization. China has been pushing for a resumption of six-party talks, the process designed to curb North Korea’s weapons program. But Seoul and Washington remain skeptical that such international efforts will change North Korea’s behavior.