BEIJING, July 1 -- Chinese shares plunged on Wednesday after a sharp rally on Tuesday, returning to the downward trend that has been occurring for two weeks, despite government efforts to boost the market.

The benchmark Shanghai Composite Index sunk 5.23 percent to finish at 4,053.70 points on turnover of 838.07 billion yuan (137.39 billion U.S. dollars). The Shenzhen Component Index dropped 4.79 percent to close at 13,650.82 points on turnover of 691.16 billion yuan.

The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, lost 3.47 percent to end at 2,759.41 points.

The market showed no signs of a sharp dive until the last hour of afternoon trading. Nearly 800 stocks fell by the daily ceiling of 10 percent.

The slump came despite easing measures from the central bank over the weekend. The People's Bank of China announced a simultaneous cut of China's interest rates and reserve requirement ratio, the amount of cash banks are required to hold, on Saturday. An official draft guideline on Monday gave China's pension fund the nod to invest in the stock market.

However, the market continued to fall on Monday with the Shanghai index down 3.34 percent and the Shenzhen index down 5.78 percent. Only on Tuesday, the market bounced back with the Shanghai index up 5.53 percent and the Shenzhen index up 5.69 percent.

The benchmark Shanghai index has shed 21.72 percent over the course of more than two weeks. It nosedived 7.4 percent on June 26, the sharpest daily drop since June 10, 2008.

Shanghai closed at fresh seven-year highs for several consecutive days in May, before another nosedive on record turnover on May 28.

On June 5, the major Shanghai index surpassed the 5,000-point mark for the first time in over seven years, jumping to 5,023.1 points.

June 12 saw the index hitting its peak at 5,178.19 points, after which the market began to the current downswing.