SEOUL: South Korea on Monday banned sending anti-Pyongyang leaflets into the North, in a move rights activists condemned as a violation of free speech and a "misguided strategy" to please the North Korean regime.

Activist groups have long sent flyers critical of North Korean leader Kim Jong Un over human rights abuses and his nuclear ambitions across the Demilitarized Zone that divides the peninsula, either flying them by hot air balloon or floating them across rivers.

The leaflets have infuriated Pyongyang, which issued a series of vitriolic condemnations earlier this year.