Industrial output dropped 2.1 percent in June, down for the second straight month, thanks to a sharp fall in machinery to produce semiconductors and flat panels, government data showed Tuesday.

The seasonally adjusted index of output at factories and mines stood at 102.2 against the base of 100 for 2010, according to a preliminary report by the Ministry of Economy, Trade and Industry. The result followed a 0.2 percent fall in May.

The second straight monthly fall, the first since December 2015, is a worrying sign for the strength of output as uncertainty remains over how much of an impact torrential rains that hit western parts of the nation in July will have on production.