An investor gestures in front of an electronic screen showing the stock composite index at a brokerage house in Beijing, August 28, 2015.[Photo/IC]

Stocks surged on Wednesday, with the benchmark Shanghai index jumping 4.9 percent after sliding below the 3,000 level.

The rush in the last hour of trading coincided with a pattern that has become associated with State support, said Bloomberg.

The Shanghai Composite Index turned around a two-day loss, closing at 3,152.26, up 147.09 points, while the Shenzhen Component Index rallied 6.5 percent to 9,890.43.

A total of 566.8 billion yuan worth of stocks changed hands at the two markets.

As of Tuesday, the outstanding balance of margin debts dropped for a fourth day to 587.1 billion yuan, data from the Shanghai bourse showed.

Transportation equipment led the gains, with China Shipbuilding Industry Co and AVIC Aero-Engine Controls Co jumping by the daily limit of 10 percent. The country's high-speed train maker CRRC Corporation rose 8.9 percent.

The industry gauge for telecommunications and software developers surged more than 9 percent among the best performing sectors.

The CSI 300 Index closed at 3,309.25, up 5 percent.