South Korea’s Defense Ministry has sent a warning message to the chief of the North Korean delegation to the inter-Korean military talks via the South-North Korean hotline at 1:27 p.m. Wednesday.

In the message, the ministry protested North Korea’s declaration of no-sail zones and firing of artillery Wednesday in the waters near the Northern Limit Line (NLL), which is the maritime border in the Yellow Sea.

The message also said the North's moves are in violation of the Korean War armistice as well as a nonaggression agreement between the two Koreas.

The ministry expressed grave concern over the North’s firing of artillery shells, urging it to immediately stop threatening acts that create unnecessary tension.