North Korea has said it has “all attack methods” at the ready after claiming South Korean drones infiltrated its capital Pyongyang, according to South Korean news agency Yonhap.

The news comes amid heightened tensions after the Hermit Kingdom’s ruthless leader Kim Jong-un said his country would sever all rail and road links to the south just days ago.

Pyongyang has claimed that the South Korean drones were “scattering leaflets” in the capital, according to Korean media reports.

North Korean state media has accused South Korea of military provocation and breaching its sovereignty by sending unmanned drones on three occasions since last week.

According to the Korean Central News Agency, they flew to Pyongyang on October 3, October 9, and October 10, reportedly to disseminate the “propaganda materials”.

North Korea has been sending thousands of “trash balloons” across the border since late May, a move it characterises as a “tit-for-tat” response to anti-Pyongyang leaflets floated by activists and defectors from the North based in South Korea.

North Korea’s military responded to the South’s latest move, urging it to end its “dangerous provocation” immediately or the region risks being plunged into “an armed conflict that could even escalate into a war”.

The military added: “[The move] is a blatant infringement of the sacred national sovereignty and safety and a violent violation of international law.”

Despite these claims from the north, South Korea’s Joint Chiefs of Staff issued a statement denying any drones had been sent by the military.

Tensions between the countries have escalated in recent months as Kim has ramped up weapons tests, and threats and South Korea has responded by strengthening its joint military exercises with the United States.

On Wednesday, North Korea said it would permanently block its border with South Korea and build front-line defence structures to cope with “confrontational hysteria” by South Korean and US forces.