SEOUL, South Korea, Oct 12, (AP): North Korea has accused rival South Korea of flying drones to its capital to drop anti-North Korean propaganda leaflets and threatened to respond with force if such flights occur again. South Korea issued a vague denial of the allegation. North Korea’s Foreign Ministry said in a statement Friday that South Korean drones were detected in the night skies of Pyongyang on Oct 3 and Wednesday and Thursday this week.

The ministry accused the South of violating North Korea’s "sacred” sovereignty and threatening its security, and described the alleged flights as a "dangerous provocation” that could escalate to an armed conflict and even war. It said North Korean forces will prepare "all means of attack” capable of destroying the southern side of the border and the South Korean military, and respond without warning if South Korean drones are detected in its territory again.

"The safety lock on our trigger has now been released,” the ministry said. "We will be prepared for everything and will be watching. The criminals should no longer gamble with the lives of their citizens.” Asked about the North Korean claims during a parliamentary hearing, South Korean Defense Minister Kim Yong-hyun told lawmakers, "We have not done that.”

He said he was still trying to assess the situation and didn’t elaborate further. It wasn’t immediately clear whether Kim was referring to South Korean military drones, or also drones possibly operated by South Korean civilians. The South’s Joint Chiefs of Staff later said in a statement that it couldn’t confirm whether the North’s claims were true, without elaborating why. The joint chiefs warned the North to "exercise restraint and not act recklessly.”

"If the safety of our citizens is threatened in any way, our military will respond with stern and thorough retaliation,” it said. North Korea is extremely sensitive to any outside criticism of the authoritarian government of leader Kim Jong Un and his family’s dynastic rule over the country. Since May, North Korea has sent thousands of balloons carrying paper waste, plastic and other trash to drop on the South, in what it described as retaliation against South Korean civilian activists who flew balloons with anti-North Korean propaganda leaflets across the border.