TOKYO, March 16 (Xinhua) -- Tokyo stocks opened slightly lower Friday as rising concerns about U.S. protectionists trade policies coupled with an influencing-peddling scandal involving Japanese Prime Minister Shinzo Abe clouded the market mood.

As of 9:15 a.m. local time (0015 GMT), the 225-issue Nikkei Stock Average dropped 20.23 points, or 0.09 percent, from Thursday to 21,783.72.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, lost 0.27 points, or 0.02 percent, at 1,743.33.

Mining, and iron and steel-related issues comprised those that declined the most in the opening minutes after the morning bell.