South Korea and the United States have vowed to step up joint military training to deter North Korea, but for residents outside the Rodriguez Live Fire Complex and other training grounds, that means more noise and possibly more security fears.

The complex north of Seoul, less than 30 kilometers from the heavily fortified border with North Korea, is one of the largest training ranges for the allies.

Windows rattled Wednesday as the allies staged one of their largest live-fire trainings in years, with howitzers and tanks blasting the hillsides in a simulated counter-attack against a hypothetical Northern onslaught.