Mainland stocks were up for a second straight day Friday, although experts warn that the modest increases may not be enough to regain the confidence of investors.

The Shanghai Composite Index rose 8.12 points, or 0.36 percent, to finish last week at 2,278.12; while the Shenzhen Component Index surged 12.04 points, or 0.13 percent, to close at 9,099.29.

Both markets sagged at opening but climbed out of their early rut on the back of gains to financial stocks as the morning session progressed. Profit taking, combined with contractions in real estate, non-ferrous metals and cement stocks sent the indices flagging in afternoon trading. Solid performances from petroleum shares ultimately kept losses in check as the day concluded.

Airline stocks also soared after Hainan Airlines Co disclosed 28.8 billion yuan ($4.63 billion) in revenue for 2012, up 9.87 percent from the previous year. The company's Shanghai-listed stock jumped to the daily limit to 4.52 yuan.

News of these earnings put the wind beneath the wings of other airlines. Air China Ltd rose 6.38 percent to 5.67 yuan. China Eastern Airlines Corp added 3.41 percent to 3.34 yuan.

In topical sectors, water desalination stocks were among the biggest winners Friday after news emerged that the National Development and Reform Commission (NDRC) issued a list of cities and industrial parks that will take part in the country's first desalination trial program. Zhejiang Hailiang Co jumped past the 10-percent daily trading limit to 7.84 yuan.

A-shares have struggled to pick up traction in recent days because investors are spooked that China will resume initial public offerings in the coming months, say analysts.

"Without any upward momentum, the markets will continue to experience mostly turbulent adjustments over the near future," Gui Haoming, chief analyst at Shenyin & Wanguo Securities, wrote in the China Business News Saturday.