SEOUL, South Korea — South Korea banned activists Monday from entering a border area where they planned to launch anti-Pyongyang leaflets into North Korea, an unusual move that the activists likened to surrender.
North Korea's military warned last week that it would strike if South Korean activists carried through with their plan to fly balloons carrying the propaganda leaflets across the border. South Korea pledged to retaliate if it was attacked.
South Korean police said they sent hundreds of officers to seal off roads and prevent activists and other people from gathering at the launch site due to security concerns.
Residents in the area were also asked to evacuate to underground facilities, according to local official Kim Jin-a.
Before Monday's action, the government had implored activists to stop their campaign, but had cited freedom of speech in not making further attempts to intervene.
South Korean activists have in the past sent leaflets across the border, and North Korea has issued similar threats without following through.
But Seoul's Yonhap news agency reported Monday that the ban on entering the border area was imposed as South Korea detected that North Korea had uncovered artillery muzzle covers and deployed troops to artillery positions in possible preparation for an attack. Yonhap cited no source for the information.
South Korean Defense Ministry spokesman Kim Min-seok told reporters Monday that North Korea was believed to have acted in line with carrying out its warning. He declined to elaborate on the North's army movement as that was confidential military information.
South Korea had bolstered its military readiness following the North's threat and would "strongly" retaliate if attacked, Kim said.
Dozens of activists, mostly North Korean defectors, planned to float balloons carrying about 200,000 leaflets critical of North Korea's young leader Kim Jong Un and his country's nuclear weapons program.
Lead activist Park Sang-hak said the entry ban was tantamount to yielding to Pyongyang's threat and his group would try to find another place to float leaflets.
"It's surrender. It's clearly surrender," he said.
Ties between the rival Koreas were badly strained after two deadly attacks blamed on North Korea killed 50 South Koreans in 2010.
The Korean Peninsula officially remains at war because an armed conflict in the 1950s ended with an armistice, not a peace treaty.
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