Image copyright AFP Image caption This weekend's talks are being held in the border truce village of Panmunjom, where the 1950-53 Korean War ceasefire was signed

North and South Korea are to hold a second round of top-level talks on Sunday to defuse growing tension, officials from the South say.

The announcement was made after several hours of negotiations on Saturday.

Senior aides to the two countries' leaders met at the Panmunjom truce village on the border.

North Korea had threatened "strong military action" if the South did not stop border loudspeaker broadcasts that had provoked a "semi-state of war".

The two sides have agreed to meet again on Sunday afternoon to "narrow down differences" as overnight talks were finally wound up after nearly 10 hours of negotiations.

Image copyright AP Image caption South Korean soldiers were on patrol on Saturday at Unification Bridge, which leads to the demilitarised zone, near the border village of Panmunjom

Image copyright AFP PHOTO / KCNA VIA KNS Image caption Kim Jong-un ordered his frontline troops to be on a "war footing" on Thursday

No media organisations were present at the talks, which took place inside the Demilitarised Zone which divides the two Koreas.

South Korea said ahead of the talks that it would be represented by national security adviser Kim Kwan-jin and Unification Minister Hong Yong-pyo, and the North would send senior officials Hwang Pyong-so and Kim Yong-gon.

Mr Hwang is seen by many analysts as North Korean leader Kim Jong-un's second-in-command.

Image copyright AP Image caption North Koreans are kept abreast of the news by reading a public copy of the daily newspaper at the platform of a subway station in Pyongyang

Image copyright EPA Image caption US aircraft have been flying sorties over the North Korean border

Image copyright AFP Image caption South Koreans living near the border have been evacuated

North Korea had earlier issued a deadline for the dismantling of banks of loudspeakers, which have been blasting news bulletins, weather forecasts and music from the South. It had moved artillery into positions to fire on them.

South Korea has evacuated almost 4,000 residents from border areas and warned that it would "retaliate harshly".

Analysis: Steve Evans, BBC Korea correspondent

Each side is represented by two members of the inner circle of the leaderships in Pyongyang and Seoul.

The difficulty is that they cannot even agree on the facts of the events which led to the current state of heightened tension.

It started when two South Korean soldiers were seriously injured by landmines in the so-called Demilitarized Zone between the two countries.

South Korea said North Korea planted the mines; North Korea said that was absurd.

Both sides say the other then fired the first shot in the artillery barrages.

The talks will not diminish the fierceness of the rhetoric between the two halves of Korea, but they may find a way for both sides to walk away safely from a dangerous situation before it explodes.

US and South Korean fighter jets have been flying in formation near the border.

The US's top military officer has reaffirmed his country's "unwavering commitment" to South Korea's defence in a phone call to his South Korean counterpart.

Chairman of the Joint Chiefs of Staff Gen Martin Dempsey and South Korea's Admiral Choi Yoon-hee agreed they would "ensure that the US and [South Korea] continue to work closely with one another to deter further North Korean provocations and defuse tensions," a Pentagon statement said.

The two Koreas remain technically at war, because the 1950-1953 conflict ended in an armistice, not a peace treaty.

Loudspeakers and psychological warfare

Image copyright Getty Images

In 2004, South Korea and North Korea reached an agreement to dismantle their propaganda loudspeakers at the border.

The broadcasts were part of a programme of psychological warfare, according to South Korean newspaper Korea Times, to deliver outside news so that North Korean soldiers and border-area residents could hear it.

Mobilising the propagandists in North Korea