SHANGHAI: China shares fell on Tuesday, with blue chips pulling back from a 13-year high touched in the previous session, as investors locked in profits in high-flying consumer firms, and as investor concerns continued to simmer over Sino-US relations.

At the midday break, the Shanghai Composite index was down 1.2% at 3,580.83 points.

China's blue-chip CSI300 index was down 1.61%, with the consumer staples sector down 0.75% and the consumer discretionary index down 3.02%.

Consumer staple and discretionary firms had lifted the CSI300 index to its highest level since January 2008 on Monday.

China-US relations continue to weigh on sentiment. China said on Tuesday it will conduct military exercises in the South China Sea this week, just days after Beijing bristled at a US aircraft carrier group's entry into the disputed waters.

US President Joe Biden wants to approach relations with Beijing with "patience," the White House said on Monday.

Meanwhile, index provider MSCI Inc said it will delete securities of five Chinese companies from some indexes as of the close on Jan. 27 in the absence of any guidance.

CGN Power Co slumped 5.95%, China Shipbuilding Industry fell 1.2% and Inspur International dropped 2.23%. China National Nuclear Power and China National Chem posted small gains.

Chinese H-shares listed in Hong Kong fell 2.18% to 11,700.24, while the Hang Seng Index was down 2.4% at 29,434.08.

Tencent Holdings Ltd dropped 6.39% a day after the surging nearly 11% amid heavy buying by mainland investors.

The smaller Shenzhen index was down 1.6%, the start-up board ChiNext Composite index was weaker by 2.39% and Shanghai's tech-focused STAR50 index was down 1.31%?.

The yuan was quoted at 6.4713 per US dollar, 0.13% firmer than the previous close of 6.4798.