Tokyo stocks extended losses Friday morning, with the benchmark Nikkei stock index losing more than 1,850 points at one point, dropping below the 17,000 threshold and marking the steepest one-day point decline since April 1990, amid growing concerns about the coronavirus pandemic.

The 225-issue Nikkei Stock Average plummeted 1,478.49 points, or 7.97 percent, from Thursday at 17,081.14.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, tumbled 95.59 points, or 7.20 percent, to 1,232.29.

Mining, real estate and air transportation issues comprised those that declined the most by the morning break.