China's Vice President Xi Jinping made his first public appearance in two weeks on Saturday following swirling speculation about the whereabouts of Beijing's leader-in-waiting.

Xi looked relaxed in television pictures which showed him visiting a university -- his first public outing since intense speculation about his health surfaced after he cancelled meetings with four foreign dignitaries this month, including visiting US Secretary of State Hillary Clinton.

He was accompanied by a trio of top party bosses for his visit to China Agricultural University in Beijing for "activities marking this year's National Science Popularisation Day", state run Xinhua said.

Xi was joined by Liu Yunshan, head of the Publicity Department of the Chinese Communist Party's Central Committee, Li Yuanchao, head of the party's powerful Organisation Department which appoints and controls personnel at every level of government and industry, and state councillor Liu Yandong, the news agency said.

In lengthy television footage aired on the 1900 (1100 GMT) bulletin on the state-run China Central Television, Xi greeted university officials, met students and gave a speech in front of a crowd which contained a handful of media.

Two pictures released by Xinhua showed a relaxed Xi speaking to a group of men at the university. They were also posted on the government website and were carried by several domestic online news portals.

China's tightly controlled state-run media has ignored Xi's disappearance from public view, focusing instead on a row over Japan's purchase of the disputed Diaoyu islands, known in Japan as the Senkaku islands.

A Xinhua report on Xi's visit to the university focused on him promoting a campaign on "food safety issues", and made no mention of the vice president's previous disappearance from public view.

His unexplained disappearance came at a highly sensitive time for China, which is gearing up for a generational handover of power.

On Thursday, he made his first public communication in nearly two weeks when state media said he had "expressed condolences on the death of old party comrade Huang Rong", who died on September 6 -- a day after Xi missed a planned meeting with Clinton.

The report in the Guangxi Daily newspaper -- mouthpiece of the Communist Party committee in China's southern Guangxi region -- marked the first public communication by Xi since he delivered a speech on September 1.

The news was published widely in China, but made no mention of Xi's wellbeing, which has been the subject of widespread speculation in recent days. Theories about his health have mentioned anything from backache to a heart attack.

Xi has been widely tipped to succeed President Hu Jintao as leader of the ruling Communist Party at a crucial meeting that is expected to be held sometime next month, before taking over as head of state in March.

His disappearance from public view attracted global attention, as well as some speculation on China's popular but heavily censored microblogs.

US Ambassador to China Gary Locke declined to weigh in on Xi during an appearance in Washington earlier this week, but noted that the heir apparent called off meetings not only with Clinton but with other foreign dignitaries. China's government has so far given no explanation for his absence. At a daily media briefing on Thursday, foreign ministry spokesman Hong Lei refused for the fourth day running to answer repeated questions about Xi's whereabouts.

Hong did, however, say that preparations for the 18th Communist Party Congress -- where Xi is expected to be named party leader -- were "well under way", adding that "Chinese authorities will release relevant information in due course".

Analysts say Xi is likely suffering from a relatively minor health complaint, as anything more serious would have prevented Hu from leaving the country to take part in last week's APEC summit.