Two minor earthquakes were detected in eastern North Korea early Tuesday.
South Korea's state weather agency said the first temblor, with a magnitude of 2.6, hit at 6:41 a.m. and was centered some 4 kilometers southeast of Changjin, South Hamgyong Province.
The second magnitude 2.8 tremor came four minutes later, rattling an area northeast of Changjin.
There were no immediate reports of damage.
The agency said it assessed both earthquakes were natural.