North and South Korea trade fire across border

South Korea fired a barrage of artillery rounds into North Korea on Thursday, after the North fired across the border to protest against anti-Pyongyang propaganda broadcasts by Seoul, a series of moves that raised tensions on the divided peninsula.

North Korea did not return fire but warned Seoul in a letter that it would take military action if the South did not stop the broadcasts along the border within 48 hours, the South's Defense Ministry said. 

In a separate letter, Pyongyang said it was willing to resolve the issue even though it considered the broadcasts a declaration of war, South Korea's Unification Ministry said.

North Korea's leader, Kim Jong Un, said he would put his troops on a "fully armed state of war" starting from Friday at 5 p.m. local time and had already declared a "quasi-state of war" in frontline areas, Pyongyang's official KCNA news agency reported.

"Commanders of the [North] Korean People's Army were hastily dispatched to the front-line troops to command military operations to destroy psychological warfare tools if the enemy does not stop the propaganda broadcast within 48 hours and prepare against the enemy's possible counteractions," South Korea's Yonhap News Agency quoted North Korean broadcaster Korean Central Television as reporting.

About 80 residents of the South Korean town where the North Korean shell fell, Yeoncheon, were evacuated to underground bunkers, and authorities urged other residents to evacuate, a Yeoncheon official said, requesting anonymity because he was not authorized to speak to the media.

In the nearby border city of Paju, residents were asked to stay home. On Baeknyeong Island near the Koreas' disputed western sea boundary — the scene of several bloody skirmishes in recent years — residents in villages near a site where South Korea operates one of its loudspeakers were also evacuated, according to island officials.

Following Thursday's exchange, Washington urged Pyongyang to halt any "provocative" actions.

Seoul began blasting anti-North Korean propaganda from loudspeakers on the border on Aug. 10, resuming a tactic that both sides had stopped in 2004. The propaganda warfare followed accusations from Seoul that Pyongyang had planted land mines on the South Korean side of the Demilitarized Zone (DMZ) that maimed two South Korean soldiers earlier this month. Pyongyang has claimed that Seoul fabricated the evidence on the land mines and demanded video proof.

Authoritarian North Korea is extremely sensitive to any criticism of the government run by leader Kim Jong Un, whose family has ruled since the country was founded in 1948.

Last October, North Korean troops opened fire at areas near Yeoncheon, after South Korean activists launched balloons there that carried propaganda leaflets across the border. South Korea returned fire, but no casualties were reported. Later in October, border guards from the two Koreas again exchanged gunfire along the border, without any casualties.

Before that, the Koreas tangled in a deadly artillery exchange in 2010, when North Korean artillery strikes on a South Korean border island killed four South Koreans. Earlier in 2010, an alleged North Korean torpedo attack killed 46 South Korean sailors.

North Korea's army said recently in a statement that the South Korean propaganda broadcasts were a declaration of war and that if they were not immediately stopped “an all-out military action of justice” would ensue.

South Korean President Park Geun-hye urged Pyongyang to “wake up” from the delusion that it could maintain its government with provocation and threats.

Thursday's artillery exchange came four days after South Korea and the United States began annual summertime military drills that North Korea calls an invasion rehearsal. Seoul and Washington say the drills are defensive in nature.

Al Jazeera and wire services