BEIJING - 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.

After the Nov 23 incident, the ROK and the US staged joint naval drills from Nov 28 to Dec 1 in waters west of the peninsula.

On Dec 3, Japan and the US launched their biggest-ever joint military exercises at bases across Japan and in the air and on waters around them, with the ROK taking part as an observer.

A series of diplomatic moves are also under way this week.

The DPRK's Foreign Minister Pak Ui-chun is visiting Russia, while US Deputy Secretary of State James Steinberg is to visit China to coordiante their stance on the Korean Peninsula.

ROK's chief nuclear envoy is scheduled to visit Russia for talks with his counterpart Alexei Borodavkin.

And New Mexico Governor Bill Richardson will visit the DPRK from Dec 16 to 20 to try to calm tensions.

China has called for an emergency meeting on the crisis between chief delegates to stalled Six-Party Talks on DPRK's nuclear disarmament.

The US, Japan and ROK have reacted coolly, saying the DPRK must first mend ties with the ROK and show seriousness about disarmament.

Russia is the sixth member of the forum.

Zhang Liangui, an expert on Korean affairs at the Party School of the Central Committee of Communist Party of China, said neither the two sides nor the US intend to go into an all-out war - but they are well prepared for it.

"The toughness of the three nations is mainly shown to their own peoples for internal political concerns," said Zhang.

"But once incidents trigger further fire, the situation is possibly out of their control."

Moreover, border clashes have "every possibility to go beyond the partial war they have prepared for to escalate into (full fighting) they would regret to see," Zhang warned.

Jin Canrong, a professor of international studies at the Renmin University of China, warned that ROK-DPRK hostilities have reached such threshold by which even accidental fire across either side of the border could create a dangerous escalation.

Jin said despite criticism from the US, China will continue with its principle of solving the conflicts through peaceful talks "to put out the fire and appeal for stability from all sides".

AFP, AP and Xinhua News Agency contributed to this story.