The Republic of Korea revoked the operation permits for two civic groups on Friday, saying their campaigns to send propaganda leaflets into the North "gravely hindered" efforts towards unification.

The decision came a month after the Democratic People's Republic of Korea blew up an inter-Korean liaison office in its border city of Kaesong in angry over leaflets criticizing its leader Kim Jong Un.

Pyongyang said such leaflets violated a series of peace agreements between the two sides.

The unification ministry in charge of inter-Korean affairs said in a statement that the government cancelled operation licenses for two local civic groups after comprehensively reviewing their explanation and relevant materials.

The ministry noted that the groups' scattering of anti-DPRK leaflets did not meet the purpose of their establishment and violated the license terms as the leafleting severely hampered the government's inter-Korean policy.

It said the leafleting endangered the lives and safety of people residing near the inter-Korean border and escalated tensions on the Korean Peninsula.

Tensions mounted on the peninsula as the DPRK demolished the inter-Korean liaison office building in the DPRK's border city of Kaesong last month in protest against the anti-Pyongyang leaflets. The DPRK has also cut all communication lines with South Korea.

About a month earlier, the unification ministry filed a legal complaint against the two civic groups for violating the inter-Korean exchange and cooperation act.

(With input from Xinhua)