TOKYO, April 12 (Xinhua) -- Tokyo stocks edged lower Thursday morning as investors became cautious amid geopolitical concerns pertaining to the U.S. and Syria.

The 225-issue Nikkei Stock Average shed 7.03 points, or 0.03 percent, from Wednesday to 21,680.07.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, lost 3.63 points, or 0.21 percent, at 1,721.67.

Rubber product and nonferrous metal issues comprised those that declined the most by the morning break.