TOKYO, March 22 (Xinhua) -- Tokyo stocks opened mixed on Thursday as investors both bought on dips and sold after Wall Street's retreat overnight after the U.S. Federal Reserve raised its interest rates.

As of 9:15 a.m, the 225-issue Nikkei Stock Average added 34.46 points, or 0.16 percent, from Tuesday to 21,415.43.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, edged down 0.81 point, or 0.05 percent, at 1,715.48.

Mining and oil and coal product issues led early gainers, while air and marine transportation issues lost ground after the morning bell.

Financial markets here were closed on Wednesday for a national holiday.