SHANGHAI - Tourists are flocking to East China's Zhejiang province in the hope of seeing the biggest tidal bore on the Qiantang River in nine years.

The Qiantang River Tide is China's most famous tidal bore and the world's largest.

The bore is formed at the mouth of the Qiantang River where it joins Hangzhou Bay by the large tidal rise and the bottleneck shape of the bay.

This year the bore will be the highest in nine years, because the time it takes the tide to rise is shorter and the flow of water is faster. The bore is expected to reach its peak on Thursday.

The bore, which usually appears from the 1st to 5th and from the 15th to 20th in the eighth month of the lunar calendar, has attracted many tourists to the province's capital Hangzhou and Haining city in northern Zhejiang during the Mid-Autumn Festival holiday.

On Monday, an estimated 170,000 visitors watched the tide, according to a China National Radio report.

Zou Jie, a senior high school student in northern Zhejiang's Jiaxing city, went to Haining to watch the tide on Monday, but said she was disappointed because the bore was smaller than she expected.

As the bore is expected to reach its peak on Thursday, the police have adopted contingency measures to prepare for potential emergencies.

Hangzhou traffic police have also imposed traffic restrictions that will last until Sunday in the western part of the city where the river empties into the sea.

Meanwhile, trucks have been banned from entering the watching areas in Haining until Sunday and only authorized vehicles will be allowed to enter the Yanguan Scenic Spot in Haining on Wednesday and Thursday.

Police warned that tide watchers must not go to dams where the tidal waves could be as high as 10 meters.