Seoul, South Korea (CNN) -- South Korea's navy fired warning shots to push a North Korean fishing boat back to its side of the Yellow Sea border Wednesday, the Yonhap news agency reported, citing military officials.

The boat crossed the Northern Limit Line at 7:18 a.m. Wednesday and then went back to its side about two and a half hours later after the shots were fired, Yonhap reported.

No casualties were reported.

Last week, North Korean and South Korean military units exchanged gunfire near their border, according to South Korean authorities.

The exchange happened after North Korean forces fired two rounds from a 14.5 millimeter machine gun at a South Korean military guard post near the border town of Chorwon, South Korea, about 73 miles (118 km) northeast of Seoul, according to an official at the Joint Chiefs of Staff.

The prickly relationship between the countries since the Korean War has had periodic conciliatory moves and flare-ups.

While there are occasional shooting incidents across the demilitarized zones, the most tense flash point on the peninsula in recent years has been the disputed maritime border in the Yellow Sea.

There were fatal naval clashes there in 1999 and 2002. In March this year, the sinking of a South Korean vessel killed 46 sailors in what a South Korean and international investigation team concluded was a North Korean torpedo attack.

Tensions though have not affected North-South Korean family reunions, which began October 30 and will end Friday at Mount Kumgang, the two Koreas' joint mountain resort in the North.

"They shared kindred feelings, inquiring after the health of their families and relatives who were not able to join the reunion," North Korea's KCNA reported on Wednesday.

"Through the reunion the separated families and relatives from the north and the south keenly realized that they cannot live separated from each other any longer but should terminate the tragic division as early as possible."