South Korean and U.S. troops have been conducting live-fire exercises this week to hone their ability to respond to potential “Hamas-style surprise artillery attacks” by North Korea, South Korea’s military said Friday.

The two forces regularly conduct live-fire and other training, but this week’s drills come after Hamas’ Oct. 7 assault on Israel raised security jitters in South Korea, which shares the world’s most heavily fortified border with rival North Korea.

Experts say the North’s forward-deployed long-range artillery guns can fire about 16,000 rounds per hour in the event of a conflict, posing a serious threat to Seoul, which is about 40-50 kilometers (25-30 miles) from the border.