SEOUL - The Republic of Korea's Navy on Friday fired warning shots at fishing boats from the Democratic People's Republic of Korea (DPRK) for violating a tense western maritime border, Yonhap News Agency reported.

In recent weeks, an increasing number of DPRK fishing boats have crossed the western border called the Northern Limit Line, a scene of deadly naval clashes between the estranged neighbors.    

The Navy has raised the alert level along the sea border in response, according to Yonhap.