Japanese authorities were silent after a sudden jump in the dollar against the yen that traders said was due to the Bank of Japan intervening in the currency market Friday to weaken the Japanese currency.

Yen coins and banknotes

In early afternoon trading in Tokyo, the dollar jumped suddenly from mid-84 yen to as high as 85.38 yen before slipping back to 84.68 yen, prompting traders to say the central bank had intervened.