North Korea's threat of counteraction raises inter-Korean military tensions.
Context
What happened: North Korea warned of an "immediate and powerful counteraction" if South Korea intrudes even "a millimeter" into its territory, after Seoul blamed Pyongyang for a Sept. 21 land mine blast at the DMZ that critically injured two South Korean soldiers.
Key numbers: Sept. 21 blast; two soldiers critically injured; 1,292 MDL signs installed in 1953, around 200 remain.
Why it matters: Seoul's military concluded North Korean mines caused the blast and conducted a mine-clearing operation with the UN Command. Pyongyang denied involvement and ruled out talks on its military sovereignty.