China has further tightened its grip on the rare earths market, raising taxes on the minerals vital to high-tech industry.

China has sanctioned state-owned companies to examine three possible strategies to block BHP Billiton's proposed takeover of mining giant Rio Tinto, a report said Monday. Strategies include forming a domestic consortium to bid for Rio Tinto, a joint bid by domestic and foreign firms, or purchasing Rio shares on the open market.

China is to relocate at least four million more people from the Three Gorges Dam reservoir area in the next 10 to 15 years to protect its "ecological safety". Senior officials who have defended the project as an engineering wonder now warn that areas around the dam are paying a heavy environmental cost.