North Korean ship crosses sea boundary, South Korean ships fire warning shots: report

South Korea fired warning shots at a North Korean merchant ship early Monday after the vessel violated the country's territorial waters, according to the military.

There were no reports of clashes between the Koreas, but the exchange came amid heightened tensions over North Korea's recent barrage of weapons tests. Bradford Betz is a Fox News Digital breaking reporter covering crime, political issues, and much more. 

The poorly marked sea boundary off the Korean Peninsula's west coast is a source of long-running animosities between the Koreas. It's a scene of several bloody inter-Korean naval skirmishes and violence in recent years, including the two attacks in 2010 that killed 50 South Koreans.