BEIJING -- Chinese stocks opened lower on Tuesday, with the benchmark Shanghai Composite Index opening 0.08 percent lower at 2,184.33.

The Shenzhen Component Index declined 0.18 percent to open at 8,364.53.

Shares of Sinopec, the country's largest oil refinery, shed 1.03 percent at the opening in Shanghai after Friday's deadly pipeline blasts in coastal city of Qingdao in east China's Shandong province.

Seven people from Sinopec and two local officials have been put in police custody after the blasts, police said on Tuesday.

The blasts on Friday has killed 55 people, left nine people missing and injured more than 160 others.

Sinopec shares tumble after deadly oil pipeline blast