The tension between Republic of Korea (ROK) and the Democratic People's Republic of Korea (DPRK) is likely to escalate as the ROK is staging a major civil defense drill this week, analysts say.
The drill comes amid a new round of live-fire naval drills running from Monday through Friday at 27 sites off the coast, although not near the disputed border with the DPRK.
Last week, the ROK staged similar live-fire drills following its major naval drill with the United States in a show of strength against Pyongyang after an exchange of artillery on Nov 23.
Analysts have warned that continuous demonstrations of strength would push the tensions on the Korean Peninsula to the brink of further clashes - which would be difficult to keep from escalating into full-fledged war.
The Wednesday drill will take place at 2 pm, with a dozen ROK fighter jets flying across the country to simulate air strikes, the National Emergency Management Agency said.
"Along with air raid sirens, people will be asked to run into some 25,000 state-managed shelters or other civilian underground facilities," said agency official Yoo Byung-koo.
The ROK usually conducts such drills without aircraft three times a year.
"Unlike previous ones, Wednesday's drill will focus on guiding people into emergency shelters," said Yoo. "This will be the biggest exercise of its kind in many years. We hope people will take it seriously."
In border areas, he said, there would be simulated strikes by DPRK's ground artillery units.
The ROK has been on high alert since the DPRK's Nov 23 bombardment of an island near the disputed Yellow Sea border, killing four people including civilians and triggered a regional crisis.
A commentary in the DPRK's leading newspaper, Rodong Sinmun, said on Monday that the ROK's claim that the DPRK had provoked the Yonphyong Island shelling incident is "a lie to the world".
It said the ROK would suffer "painful consequences" of the tension while the outsiders would benefit - and that ROK's action to "jugulate" compatriots with outsiders is an intolerable "move of (a) traitor".
Top US and ROK military officers last week vowed more joint drills and promised a tough response to future attacks.