North Korea on Thursday fired artillery shells near the disputed maritime border with South Korea for a second day, dpa quoted news reports from Seoul as saying. The North began firing towards the South Korean island of Yeonpyeong near the Northern Limit Line (NLL) in the Yellow Sea at 8:15 am (2315 GMT Wednesday), the Yonhap news agency said, quoting a defense official. The shells landed in North Korean waters, similar to Wednesday's firing. South Korea returned fire Wednesday when North Korea fired as many as 100 shells in the waters north of the de-facto Korean maritime borderline, but stressed those had been warning shots. There were no reports that South Korea returned fire on Thursday. The General Staff of the Korean People's Army (KPA) Wednesday confirmed North Korea's fire in the Yellow Sea, saying it was part of an annual drill.