<br/>North Korea has fired artillery near its disputed maritime border with South Korea, a day after the two exchanged shots in the same area. Yonhap news agency reports, the North fired several rounds of artillery toward the border early on Thursday.<br/><br/>AP quoting an unnamed official reports that the shells landed in North Korean waters. The South had not responded, the official said. South Korea yesterday called the North's firing "provocative". <br/><br/>But the North said the firing had been part of an annual military drill which would continue. <br/><br/>The second incident in as many days comes after the North designated two no-sail zones in the area, including some South Korean waters, until March 29.