BEIJING, July 21 -- China's benchmark Shanghai Composite Index hovered around the 4,000-point level on Tuesday, as market sentiment remained cautious following the recent drastic ups and downs.

The index was up 0.64 percent to close at 4,017.68 points.

The smaller Shenzhen Component Index gained 0.86 percent to close at 13,315.56 points. The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, rose 1.21 percent to end at 2,882.9 points.

This is the fourth consecutive day of gains following government moves to arrest a freefall that saw the key index plunge over 30 percent from its June 12 peak.

Trading was thin on Tuesday, with total turnover on the two bourses totalling 1.2 trillion yuan (197.2 billion U.S. dollars).

Shares related to highways, airports and railways led the gains. Hubei Chutian Expressway Limited surged by the daily limit of 10 percent to end the day at 6.55 yuan per share.

China Southern Airlines, China Eastern Airlines and Hainan Airlines all saw their shares soaring by the daily limit.

Guo Yiming, an analyst with Shaanxi Jufeng Investment Information Co., said whether the upward momentum can be sustained is still in question given the thin trading.