South Korea has imposed fines on seven members of a local civic group for their unauthorized contact with North Koreans in China last month, officials said Monday.

Without the government's approval, they held a meeting with their North Korean counterparts in Shenyang in late May to discuss how to hold a joint summit event designed to commemorate the historic inter-Korean summit in 2000.

Seoul's unification ministry earlier rejected the group's request for approval of their contact, citing the grave situation following Pyongyang's nuke and missile tests early this year.

By law, South Koreans are required to win Seoul's approval for either meeting with North Koreans in a third country or visiting North Korea. The North's consent is also required for South Koreans to travel to the communist nation.

"As they violated the law on inter-Korean exchanges, the government has slapped fines worth less than 2 million won ($1,705) each on the seven people," said a government official.

In Shenyang, the South and North's groups agreed to hold a joint event this month to mark the 16th anniversary of the inter-Korean summit in the North's border city of Kaesong.

They also decided to host a jointly-arranged celebration for the 71st anniversary of Korea's liberation from Japan's 1910-45 colonial rule in August in Seoul.

The ministry said it also rejected the group's bid to visit Kaesong for the summit event slated for Wednesday.

A summit between then-South Korean President Kim Dae-jung and then-North Korean leader Kim Jong-il, the father of the current leader Kim Jong-un, was held in Pyongyang on June 15, 2000. It produced a landmark joint declaration that outlines inter-Korean reconciliation and economic cooperation.

The unification ministry said that North Korea's nuclear weapons program poses a "grave" threat to peace on the divided peninsula, calling on Pyongyang to give up its nuke arsenal.

"North Korea's move to develop nuclear weapons is to hurt the spirit of cross-border agreements," it said in a statement. "The North should suspend its reckless provocations and abandon its nuclear weapons program so as to change for the better."

South Korea has suspended almost all inter-Korean civilian exchanges and has not allowed South Koreans to visit North Korea after the latest nuke test in January.

The two Koreas are still technically at war since the 1950-53 Korean conflict ended in a truce, not a peace treaty. (Yonhap)