"The won fell against the dollar in April due to geopolitical risks and remittances of dividends by foreign investors," the statement said.

Tensions heightened on the Korean Peninsula in recent weeks over Washington's possible pre-emptive strike against North Korea over its nuclear and missile programs. Pyongyang has said it is ready for a war if the US takes military action.

Meanwhile, the Korean currency posted 7.4 won in daily value changes against the dollar in April, up from 6.1 won a month earlier, it said.

The won finished at 1,137.9 against the greenback at the end of April, compared to 1,118.4 a month earlier.

Foreign investors poured a net $2.2 billion into the local financial markets -- $990 million in stocks and $1.21 billion in bonds -- in April, the BOK said. It was down from foreign injections worth $5.49 billion a month earlier.

The credit default swaps premium for foreign exchange stabilization bonds came to 56 basis points in April, up from 48 basis points a month earlier, the BOK said. (Yonhap)