South Korea ? North and South Korean officials held talks today on a joint industrial complex just days after the North renewed tensions between the neighbors by firing artillery toward their disputed sea border.

North Korea lobbed dozens of shells near the western sea border during a military exercise last week, prompting South Korea to respond with a barrage of warning shots. No casualties or damage were reported, and South Korean officials said North Korea’s artillery landed in the water.

The poorly marked sea border is a constant source of tension between the two Koreas. Their navies fought a skirmish in November that left one North Korean sailor dead and three others wounded, and engaged in bloodier battles in the area in 1999 and 2002.