North Korea on Tuesday fired dozens of artillery shells at a South Korean island, setting buildings on fire and prompting a return of fire by the South, Seoul's military and media reports said.

A witness said residents of the island of Yeonpyeong, off the west coast of the peninsula near a disputed maritime border, had been evacuated during the shelling.

The exchange, which lasted for about an hour and then stopped abruptly, was the most serious between the two Koreas in years.

South Korea's military said one marine had been killed and three seriously wounded in the shelling, the biggest attack in years. The island is about 3 km south of the sea border and 120 west of Seoul.

YTN television quoted a witness as saying 60 to 70 houses were on fire after the shelling and TV footage showed plumes of smoke coming from the island. It said a South Korean fighter jet had been deployed to the west coast after the shelling.

"Houses and mountains are on fire and people are evacuating. You can't see very well because of plumes of smoke," a witness on the island told YTN. "People are frightened to death and shelling continues as we speak."

The South Korean central bank said it would hold an emergency meeting to assess the possible market impact of the shelling.

South Korea's military confirmed the exchange of firing, without providing more details.

The attack comes just as a US envoy is travelling to the region after revelations that the North is moving ahead with uranium enrichment, a possible second path to manufacture material for atomic weapons.

"It's unbelievable," said Zhu Feng, professor of international relations at Peking University. "Today's news proves that North Korea, under unprovoked conditions, shot these South Korean islands. It's reckless provocation. They want to make a big bang and force the negotiations back into their favour. It's the oldest trick."

There was no immediate comment from the White House and State Department. China, the closest the isolated state of North Korea has to an ally, expressed concern about the incident.

The impoverished North depends heavily on China for economic and diplomatic support and its leader, Kim Jong-il, has visited China twice this year, in part to gain backing for the anointment of his son to eventually take over the family dynasty.

CHINA CALLING FOR TALKS

Meanwhile, China said Tuesday it was "imperative" six-nation talks to end North Korea's atomic ambitions be restarted, amid alarm over Pyongyang's latest nuclear claims and artillery fired at South Korea.

"What's imperative now is to restart six-party talks as soon as possible," foreign ministry spokesman Hong Lei told reporters when asked to comment on North Korea's claims it has an operational uranium enrichment programme.

He spoke as the US envoy headed to China to seek its help in curbing North Korea's new nuclear project, and shortly after North Korea's firing  onto the South Korean island. 

"It is China's consistent and firm position to realise de-nuclearisation on the (Korean) peninsula through dialogue and consultation," Hong said.

"We hope parties make joint efforts to create conditions for the resumption of six-party talks," he added, repeating a call China makes routinely in the effort to dismantle North Korea's nuclear programme.

Source: Reuters/AFP