A North Korean defectors' group in South Korea will reportedly push ahead with a plan to send anti-Pyongyang leaflets across the border later this month.

The planned campaign comes amid heightened tensions between the two Koreas after Pyongyang cut off all communication lines with South Korea on Tuesday, taking issue with the leaflets sent by defectors into the North. 

According to police on Wednesday, Fighters for Free North Korea, an organization of North Korean defectors, announced a plan to release balloons carrying one million anti-North Korea leaflets on June 25 in the border area.

The group is said to have already secured enough hydrogen gas to send ten balloons, putting police on alert.

As of Tuesday, about 460 police officials have reportedly been deployed to 38 locations in the Paju, Yeoncheon and Ganghwa areas near the inter-Korean border to monitor and prevent the campaign.