Industrial production fell a seasonally adjusted 1.3 percent in August, declining for the second straight month on weakening exports to China and other countries, a preliminary report by the industry ministry showed Friday.

With the index of output at factories and mines falling to 90.5 against the base of 100 for 2005, the lowest since May 2011, the Ministry of Economy, Trade and Industry downgraded its basic assessment of output, saying it "appears to have weakened."

"The data demonstrate that external demand is weak," a METI official said, noting the territorial row with China over the Senkaku Islands may further weaken output in the next months.