North Korea said it would hand over the body a South Korean man killed by its troops if it is found during a search operation, but warned South Korea from sending any warships into the North’s territorial waters, state media reported on Sunday.

North Korean leader Kim Jong Un issued a rare apology on Friday after South Korea’s military said that the North’s soldiers had killed the man, doused his body in fuel and set it on fire near the sea border.

In its report on Sunday, the KCNA state news agency called it an “awful case which should not have happened” but warned that South Korean naval operations near the site of the incident threatened to escalate tensions.