HANGZHOU - Roaring tides along the Qiantang River in East China's Zhejiang province have attracted more than 70,000 tourists to the area, prompting authorities to take measures to ensure that all of the tourists remain safe.

The Qiantang River tidal bore is the world's largest in terms of height and speed. Every year, massive waves crash along the banks of the river near the city of Haining, drawing large numbers of tourists to watch the spectacle.

Local resident Wu Kun said he is always shocked to see the size of the waves, even though he has seen the tidal bore many times before.

"I bring my foreign friends to watch the tides every year. The tidal bore is awesome and without parallel," Wu said.

This year's tidal bore has been highly anticipated, as the Qiantang River is only now recovering from a seven-year-long drought, according to the local maritime affairs department. Heavy rains in June brought two mild flood peaks and boosted the enthusiasm of local residents, the department said.

According to astronomical tide forecasts by the State Oceanic Administration (SOA)'s East Sea Center, this year's tide-watching period will last until October. The local government has been working since the start of the season to encourage tourists to stand clear of the riverbanks and watch the tides from a safe distance.

Official statistics show that 27 tourists have died in tidal bore-related accidents since 2005. The most recent accident occurred on August 31, when 30 tourists were sent to a hospital for emergency treatment after being swept into the river by a large wave. Nine of the tourists had to stay in the hospital for several days, but no deaths were reported.

"I felt like I was falling down a slide. If it wasn't for the soft grass on the slope of the riverbank, I could've been seriously injured," said tourist Yang Zhen.

More than 700 police officers have been stationed along the riverbank to ensure that the tourists remain safe while watching the tides.