Speculation is rife that Kim Jong Un made a surprise visit to China after media reports about arrival of a special train believed to be carrying the North Korean dictator.

Speculation is rife that Kim Jong Un made a surprise visit to China after media reports about arrival of a special train believed to be carrying the North Korean dictator. Japanese broadcaster Nippon TV showed footage of a train -- similar to the one used for foreign visits by Kim's late father Kim Jong Il -- at a Beijing station. If confirmed, it would be Kim's first overseas trip since he took over power in 2011 after his father's death. (Reuters)

The arrival of a special train in Beijing and unusually heavy security at a guesthouse where prominent North Koreans have stayed in the past have fueled talk that Kim was making his first visit to China as the North's leader. (Reuters)

Japanese broadcaster NTV reported that the green and yellow train appeared very similar to the one that Kim's father and predecessor as North Korea's leader, Kim Jong Il, took to Beijing in 2011. (Reuters)

Video that aired on NTV also showed a motorcade of black limousines waiting at the train station and rows of Chinese soldiers marching on what appeared to be a train platform. The video did not show anyone getting off the train. (Reuters)

The limousine was seen about 10 minutes later entering the station under a heavy security presence. The station itself was closed to the public in an unusual security measure. Chinese foreign ministry spokeswoman Hua Chunying, however, said at a media briefing that she had "no information for the moment" about reports that Kim visited China. "The information will be published in due course," she said. (Reuters)

A Reuters reporter saw a convoy leave Beijing's Diaoyutai State Guest House, where senior foreign leaders often stay, and drive north on Tuesday morning. It was unclear where the convoy was headed. Later, a Reuters journalist saw what was believed to be the delegation's train pulling out of a Beijing station. The group was reported to have arrived in China on Sunday after crossing from North Korea in the border city of Dandong. (Reuters)

China has not confirmed any visit by a North Korean but has not totally censored speculation. There were posts on Chinese social media talking about the possibility Kim Jong Un was in China, some citing family members in Dandong. The rail journey between Dandong and Beijing covers more than 1,100 km (680 miles). It takes at least 14 hours by ordinary service, according to Chinese railway timetables. (Reuters)

Past visits by Kim Jong Il to China were surrounded in secrecy, with Beijing only confirming his presence after he had crossed the border by train back into North Korea. North Korea's state-run media had no reports of a delegation traveling to China. (Reuters)

Such a trip would be seen as a potential precursor to Kim's planned summit with South Korean President Moon Jae-in in late April and his anticipated meeting with Trump by May. Analysts, however, questioned whether Kim would make the visit to Beijing himself rather than send an envoy. Whoever was on the train, their visit to Beijing appeared to be a short one. On Tuesday afternoon, a vehicle convoy led by a motorcycle escort was seen heading in the direction of Beijing's main railway station. (Reuters)

The conservative South Korea Chosun Ilbo newspaper, citing an unnamed senior intelligence official, said the delegation had included Kim and that he had since left to return to North Korea. South Korea's left-leaning press Hankyoreh also reported Kim had travelled to Beijing for meetings with Chinese President Xi Jinping on Monday afternoon before leaving for a "third location" on Tuesday. It did not cite specific sources. The Hankyoreh did not specify where the "third location" was but said it could be in China. (AP)

Cars in the convoy were identified by yellow stickers but carried no diplomatic license plates. South Korea's presidential office said it could not confirm reports that the train carried Kim nor a separate report that Kim's sister was onboard. (Reuters)

South Korean analysts were doubtful the visitor is Kim. Since succeeding his father as leader in 2011, Kim has touted an image of his country as diplomatic equal to China and it's unlikely he would sneak into Beijing for his first face-to-face meetings with the Chinese leadership, the analysts said. (Reuters)