South Korea's current account surplus narrowed in March from a year earlier due to an increased deficit in the service balance, central bank data showed Thursday.

The country's current account surplus reached $5.93 billion in March, compared with a surplus of $10.55 billion a year earlier, according to the preliminary data from the Bank of Korea.

The figure represents a surplus for 61 months in a row. The current account is the biggest measure of cross-border trade.

The BOK said the widened deficit in the service balance and increased imports are to blame for the reduction of the current account surplus.

The BOK said the service balance deficit widened to $3.27 billion in March from a deficit of $920 million a year earlier due to a rise in overseas trips.

The number of South Koreans who traveled to foreign countries jumped 23.7 percent year-over-year to more than 1.94 million in March, according to data compiled by the Korea Tourism Organization.

Chung Kyu-il, director general of the Economic Statistics Department at the BOK, said a sharp decline in the number of Chinese tourists in South Korea is also to blame for the rise in the service balance deficit.

The data compiled by the Korea Tourism Organization showed that a total of 360,782 Chinese visited South Korea in March, compared to 601,671 from a year earlier. China has banned the sale of tour packages to South Korea in an apparent retaliation against Seoul over a US missile defense system.

Seoul and Washington began to deploy the US missile shield in South Korea to counter North Korea's evolving nuclear and missile threats.

Still, China has repeatedly pressed South Korea and the US to cancel the deployment and withdraw the missile defense system, claiming it could hurt China's security interests.

The latest data showed the primary income account deficit narrowed to $590 million from a deficit of $870 million a year earlier.

Exports rose 12.8 percent year-over-year to $50.38 billion, with imports surging 27.5 percent to $40.58 billion. (Yonhap)