South Korea on Friday returned home all four North Korean fishermen rescued near the Yellow Sea border a day earlier, the Seoul government said.

The four were found drifting aboard two small sinking boats Thursday in waters about 6 kilometers south of the western maritime border near the South Korean island of Baengnyeong.

All of them were handed over to North Korea at the inter-Korean truce village of Panmununjom Friday, the Ministry of Unification said.

"The four North Korean citizens rescued Aug. 11 while drifting in western waters were sent back today through Panmunjom," the ministry said in a news statement.

Another North Korean boat with three fishermen was also found drifting near the maritime border later Thursday. They were also sent home Friday after the South Korean Navy refueled their vessel, the ministry said in an earlier announcement.

It is not uncommon North Koreans who drift to the South, even by accident, decide to stay here, but many also decide to return home especially when they have family in the North.

In February, a group of 31 North Koreans drifted to the South on a wooden boat. All but four who wanted to stay back were allowed to go home.

More than 20,000 North Koreans have defected to the South since the Korean War ended in 1953. Most of them arrived here after first fleeing to China. (Yonhap News)