The government says it will swiftly send back home two North Korean boats that separately drifted into South Korean waters off the east and west coasts Thursday afternoon.

The Defense Ministry said in a statement Thursday that the North Korean vessel located in the East Sea and its three crewmen will be returned to the North on humanitarian grounds on Friday at the earliest, once the vessel is repaired.

The statement said the North's Navy had sent a radio message to the South asking for assistance in rescuing the five-ton ship that had drifted across the inter-Korean maritime border in the East Sea due to engine trouble and lack of fuel late Thursday afternoon. The boat was towed to a port in Goseong County.

In a separate incident, a North Korean barge carrying two crewmen drifted across the western sea border shortly after six o'clock and was towed to Incheon Port, west of Seoul in the evening. The Defense Ministry said the North had sent a similar radio message for help in salvaging the troubled ship.

The two incidents mark the first time civilian ships have been safely rescued at the maritime border by means of the military communication hotline that the two Koreas opened earlier this year.

In June, South and North Korea agreed to have their navies share a radio frequency and use the same flag signaling system to avoid accidental clashes on the poorly marked maritime border.