Chinese mainland stocks opened higher Tuesday morning as investors returned from a long holiday weekend to play catch-up with a global rally. The benchmark Shanghai Composite Index added 0.21 percent, or 7.24 points, to 3,491.63, while the Shenzhen Composite Index on China's second exchange edged up 0.32 percent, or 7.23 points, to 2,269.31. Hong Kong's market was closed for a public holiday. dan/rma