The nation's police chief said there are no legal grounds to prevent North Korean defectors’ groups from flying anti-Pyongyang propaganda leaflets north of the border, despite such activities prompting the regime to send trash-carrying balloons in retaliation.

Speaking to local reporters on Monday, National Police Agency Commissioner General Yoon Hee-keun said it remains unclear whether the trash balloons pose an imminent and serious threat to public lives and health, which would provide a legal basis for police to restrict such activities.

Yoon then referred to an incident in October 2014, when Pyongyang fired anti-aircraft guns to shoot down the balloons carrying propaganda leaflets, posing a serious threat to border area residents.

An official for the national police said the sending of leaflets, which was banned under the Development of Inter-Korean Relations Act, is currently being allowed after the Constitutional Court decided that the ban restricted the people’s freedom of expression.

Asked whether he will maintain this position if the North continues to send the balloons, Yoon said a decision would have to be made in consideration of a series of related developments.