SOUTH KOREA HAS WARNED of retaliation if it is the subject of any further military action by North Korea.

Two soldiers were killed and 19 other people, including civilians, were wounded today when North Korea fired a series of shells at the South Korean island of Yeonpyeong.

South Korea returned fire. Each side blamed the other for sparking off today’s unrest, saying opposing forces fired first.

The incident is the most serious to have developed between the two nations since the Korean War in the 1950s. Up to 70 homes and buildings on the island were destroyed by fire resulting from the artillery.

This footage compiled by Russia Today shows people on the island fleeing for cover during the attack:

Al Jazeera reports that the US has about 28,000 military personnel stationed in South Korea, but has not deployed any further personnel to the area.

US defence department spokesperson Col Dave Lapan said it was too early to say the US was considering any action in response to today’s events, but was monitoring the situation and talking with its allies.

President Barack Obama described the incident as an “outrageous, provocative act” by North Korean leaders, according to the BBC. Refusing to speculate on what sparked the attack, Pentagon press secretary Geoff Morrell said the North Korean government was “extremely unpredictable”, VOA News reports.

South Korea’s President Lee Myung-bak held emergency meetings with his national security council today, and warned North Korea he was prepared to respond with missile strikes if further provoked.

The island lies close to a disputed maritime border on the west of the Koreas. The Christian Science Monitor reports that although the attack was directed at South Korean marines on the island, it is the most serious attack on land since the Korean War.

Tensions between the two countries have been particularly tense since the South accused the North of sinking one of its ships in March, killing 46 people. Last month, South Korean troops posted along the border said that bullets were fired at their army post from across the border. They fired in response, but no one was injured in the incident.

Nuclear defence?

Today’s attack have stoked fears over North Korea’s nuclear development programme.

Stanford professor Sig Hecker toured a North Korean nuclear facility earlier this month and has commented on how impressed he was with the plant, according to Foreign Policy magazine.

Hecker said the facility “was just stunning”, adding: “I said ‘Oh my God, they actually did what they said they were going to do”.

He said what he saw while touring the plant suggested to him that it carries serious implications for international diplomacy and allows the North Koreans to make the same argument as Iran about its uranium facility – namely, that it’s for producing energy for domestic use.

In his report, Hecker writes that the nuclear facility “appeared to be designed primarily for civilian nuclear power”, but could be readily converted to produce “highly-enriched uranium (HEU) bomb fuel”.