LHASA, May 4 (Xinhua) -- Tibet's tourism departments have promised to freeze ticket prices at all tourist sites within the autonomous region this year.

Since the opening of the Qinghai-Tibet Railway on July 1 last year, Tibet has witnessed a rapid development of tourism. The number of visitors to Tibet reached 116,000 in the first quarter, up 15.8 percent from the same period last year, according to the Tibet Regional Tourism Bureau.

Tourism income during the first quarter reached 105 million yuan (13.64 million U.S. dollars), up 16.5 percent from the same period last year.

In the run-up to the peak season, the bureau is drawing up plans to control visitor numbers at the top attractions, such as the Potala Palace, the former residence of Dalai Lamas, because of the fragility of the ancient buildings.

The opening hours of the Potala Palace will be extended from July to September, and the tickets must be booked in advance.

Lhasa also plans to build a replica of the Potala Palace in miniature.

The Potala Palace used to receive 1,400 tourists every day before the railway was opened. As many as 6,000 tourists flocked to the site in peak season in the latter half of 2006.

The Qinghai-Tibet Railway, the first to link Tibet to the rest of China, starts in Xining, northwest China's Qinghai Province, and ends in Lhasa. Before the opening of the 1,956-km railway, tourists could only reach Tibet by air or road.

Tibet hosted more than 2.51 million tourists last year, of whom 154,800 were from overseas. They spent 2.77 billion yuan in the region.

The region was expected to host three million tourists and bring in 3.4 billion yuan this year, said Jin Shixun, director of the development and reform commission of the Tibet autonomous regional government.