North Korea leader 'makes visit to China'

North Korean leader Kim Jong-Il was believed to be visiting key ally China on Thursday, possibly with his youngest son and presumed successor, officials, media reports and Chinese residents said.

The apparent trip, which was not confirmed by either Beijing or Pyongyang, dashed hopes of a meeting with former US president Jimmy Carter who is on a mission to North Korea to try to win the release of a jailed American.

"Judging from circumstances, Chairman Kim might have left for China early Thursday morning," a senior South Korean official told AFP on condition of anonymity.

Residents of Jilin in northeastern China said a delegation had visited and left the city Thursday amid tight security.

The trip -- which would be Kim\'s second to China this year -- comes amid increasing speculation about Kim\'s successor and efforts by Beijing to revive North Korean nuclear disarmament talks despite high tensions on the peninsula.

Analysts in South Korea said Kim was seeking to obtain China\'s blessing for his successor, widely expected to be his youngest son Kim Jong-Un, and gain desperately needed economic assistance from its main source of aid.

They also suggested that Kim\'s departure for China while Carter was in Pyongyang meant the North considered it too early to seek a breakthrough in tense relations with the United States.

South Korea\'s Yonhap news agency said Kim might be accompanied by Kim Jong-Un, 27, who is expected to be named to the ruling North Korean party leadership at a rare meeting next month.

Speculation about succession has intensified since Kim Jong-Il, now 68, suffered a stroke in August 2008, but he has since recovered sufficiently to work.

"Kim may have decided to tackle this issue in person as China has yet to reach an understanding about the succession at a time when the nuclear issue has not yet been resolved," Professor Yang Moo-Jin of the University of North Korean Studies told AFP.

Yonhap quoted an unidentified senior official as saying that "signs have been detected" that Kim made the visit to China on a special train.

It quoted a diplomatic source in Beijing saying the train had travelled north and apparently avoided its usual route, which would have taken him through an area hit by widespread flooding.

In Jilin, a resident said the group visited a middle school on Thursday that had been attended by Kim\'s father and former North Korean leader Kim Il-Sung as a boy.

"They arrived in the morning. There were many police in the streets and the roads were blocked," a woman who works at a restaurant adjacent to the Yuwen Middle School told AFP by phone.

"They have left. The police have left and the roads were reopened," she said, declining to give her name.

An employee at a park in Jilin also told AFP Kim had made a visit, while in the border city of Jian, a staff member at the Xiang Gang Cheng Holiday Hotel said the delegation had stayed there.

It was unclear where the delegation was later Thursday, or whether its ultimate destination was Beijing. Pyongyang and Beijing have made it a rule not to confirm Kim\'s trips to China, which he last visited in May and met President Hu Jintao.