President Hu Jintao of China was shielded from demonstrators amid tight security on Saturday as he toured Hong Kong to mark the 15th anniversary of the territory's handover from Britain in 1997.
Police briefly detained and questioned a reporter who shouted a question about the crushing of the democracy movement at Tiananmen Square in 1989.
Giant barricades have been erected around Mr Hu's hotel and a convention hall where he attended the inauguration on Sunday of the territory's new chief executive, Leung Chun-ying.
Police manned every intersection and building entrance nearby.
AFP reports the security arrangements for the visit have been compared to "war time" measures.
Metal fences will keep potential demonstrators far away from Mr Hu and his delegation.
"In the coming two days, I hope to be able to walk more, see more and personally feel the development of Hong Kong, understand the life and expectations of the Hong Kong people," he said on arrival.
China has promised the direct election of Hong Kong's leader in 2017.
Mr Leung, 57, succeeds Donald Tsang as chief executive.