Potala Palace in Tibet (Xinhua File Photo)

Tibet's Potala Palace and Norbu Lingka Palace received more than 1.63 million tourists last year, a 53.7 percent increase year-on-year, said the regional source on Thursday.

"Potala Palace has taken measures to improve its reception capability so as to meet the needs of increasing number of visitors from home and abroad," said Yu Dawa, director of the region's cultural relics bureau.

"However, to protect Potala Palace, no more than 2,300 visitors are allowed to enter the palace per day," Yu said.

This year, Tibet expects to receive at least five million tourists with the region's tourism revenues estimated to hit six billion yuan (about 800 million U.S. dollars).

Tourism is Tibet's main industry. The region received record-high 4.02 million tourists in 2007, a 64 percent increase year-on-year.

Yu attributed the surge in tourists mainly to the operation of the Qinghai-Tibet Railway that was completed in July 2006.

Statistics showed that in the first full year of operation of the railway to last June, more than 1.5 million visitors, accounting for over half of the total tourists, took the train to the region. Another 1.4 million arrived by air.

The renovation projects on Potala Palace, Norbu Lingka Palace and Sagya Monastery were still going on. At a cost of 330 million yuan, the projects began in 2002 and were expected to be finished this year.

Starting in January, the palace doubled the ticket price to 200yuan (27.4 U.S. dollars) in the peak summer season and 100 yuan in the winter season.