SEOUL, South Korea (AP) — North Korean leader Kim Jong Un’s powerful sister on Saturday accused South Korea of ​​deliberately avoiding responsibility for the allegation South Korean drone flights over the northern capital and warned of a “terrible catastrophe” if they continued.

Kim Yo Jong’s statement came a day after North Korea’s Foreign Ministry claimed that South Korean drones carrying anti-North Korean propaganda leaflets were spotted in the night sky over Pyongyang on October 3 and Wednesday and Thursday this week.

The ministry said North Korean forces would prepare “all means of attack” capable of destroying the southern side of the border and the South Korean military, and would respond without warning if South Korean drones were detected on their territory again.

South Korea’s defense minister initially denied the accusation, but the South Korean military later adjusted its response, saying it could not confirm whether the North’s claims were true or not.

In comments published by state media, Kim, one of her brother’s top foreign policy officials, said the South Korean military’s vague statements should be taken as evidence that it was “either the main culprit or accomplice in this incident.”

“If the military stood by while its own citizens used drones, a widely recognized multi-purpose military tool, to violate the sovereignty of another country and thereby increase the risk of armed conflict with a potential adversary, it would amount to deliberate connivance and collusion in a moment,” she said.

“As soon as a South Korean drone is spotted again in the skies over our capital, a terrible catastrophe is sure to occur. Personally, I hope that doesn’t happen.”

South Korea’s military and government did not immediately respond to Kim’s comments.

Tensions between the Koreas are now at their worst level in years as the pace of both North Korea’s missile testing and the South’s joint military training with the United States have accelerated in lockstep. Hostility has been heightened in recent months by Cold War-style psychological warfare campaigns between the Koreas.

Since May, North Korea has sent thousands of balloons filled with paper waste, plastic and other trash to the South, in what it said was retaliation against South Korean civilian activists who flew balloons carrying anti-North Korean propaganda leaflets across the border.

The South Korean military responded to the North’s balloon campaign by using border loudspeakers to broadcast propaganda and K-pop into North Korea.

North Korea is extremely sensitive to any criticism from outside of the authoritarian government of leader Kim Jong Un and the dynastic rule of his family.

South Korean officials have expressed concerns that North Korea may seek to increase pressure on Seoul and Washington ahead of the U.S. presidential election in November. Experts say Kim’s long-term goal is to eventually force Washington to accept North Korea as a nuclear power and negotiate security and economic concessions from a position of strength.

In written answers to questions from The Associated Press this month: South Korean President Yoon Suk Yeol said North Korea is likely preparing major provocations related to the U.S. election, possibly including test-detonating a nuclear bomb or flight-testing an intercontinental ballistic missile test to attract Washington’s attention.