SEOUL, June 20 (Yonhap) -- A U.S. spy plane flew over South Korea on Saturday, an aviation tracker said, the latest in a series of flights apparently aimed at monitoring North Korea amid Pyongyang's threat to take military action against the South.
The U.S. Air Force E-8C Joint Stars took off from Japan's Kadena Air Base on Friday evening and flew over South Korea until early the next day, "No callsign" tweeted.
Earlier, other U.S. spy planes, including the RC-135W Rivet Joint and the Navy's EP-3E, were also spotted flying over South Korea.
The flights took place as tensions on the peninsula have escalated after North Korea threatened to send troops to disarmed border regions and abolish an inter-Korean tension-reduction deal in anger over anti-Pyongyang leaflets sent across the border by activists here.
On Saturday, the North's state media said Pyongyang is preparing to send its own anti-Seoul leaflets across the border.
The leaflets will be sent "as soon as the areas close to the boundary between the North and the South are opened and their entry into the areas is approved according to relevant procedures," the Korean Central News Agency said.
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