Some North Korean troops staging an annual winter exercise returned to their bases hours after the death of their leader Kim Jong-Il was announced, a South Korean military official said today.
"We've learned that some units in the middle of their winter exercise went back to their bases overnight (Monday)," the official told AFP on condition of anonymity.
A spokesman for the Joint Chiefs of Staff could not confirm the report on the cancelled exercise. But he said all the North's military units had tightened security following announcement of Kim's death and most units along the border were flying flags at half-mast.
The South has put its own military on emergency alert but the spokesman said no unusual activities have been seen on the other side of the heavily fortified border.
The North's military also focused on strengthening security after the death of the country's founder Kim Il-Sung in 1994.
The Daily NK, a Seoul-based online newspaper run by defectors, has reported a security clampdown in at least one city in the North. It said armed troops were standing guard every four metres in the centre of the northeastern city of Musan and had chased away small traders from the area.