Image copyright AFP

In the past few days, North Korea has sent some one million leaflets across the border to the South, attached to helium balloons.

Activists have been sending leaflets the other way for decades, but it's a long time since the North did this. South Koreans have been told to hand in what they find, and soldiers have been out looking for them.

The BBC's Kevin Kim got hold of some of the leaflets and explained what the messages can tell us about the North.

'Stop with any further hostilities or stupid actions that can threaten your security!'

These slogans are very direct. I'm not sure if a senior officer just says it and someone jots it down, but they feel spontaneous and lacking subtlety.

They are quintessentially North Korean, the sort of language you see in their media and propaganda, right down to details like the colours and quality of paper used.

The leaflets sent up North by South Korean activists are more subtle.

Some go into the family history of Kim Jong-un and in the North, where talking about the "royal family" is so taboo it can land you in a prison camp, this feeds into curiosity people might have about their leader.

'Park Geun-hye and her clan are dogs that have gone crazy. We should beat them down for using psychological warfare and worsening inter-Korean relations!'

The North Koreans have been known to be sexist and racist in the past - they have called President Park Geun-hye a prostitute and have published pictures showing US President Barack Obama as a monkey.

Another leaflet dropped on the South had a cartoon of Ms Park in a red bikini being thrown into a rubbish bin as "human filth".

Most South Koreans don't actually take it that seriously, being a democratic society with diverse political views.

'Psychological warfare against the North is lighting the fuse of war. Stop the loudspeaker broadcasts immediately!'

South Korea turned on its huge banks of loudspeakers after the North's claim to have tested a hydrogen bomb earlier this month. The North does have its own speakers but they are so faint and unclear even the military along the border can't hear them.

What is new is that the North has chosen a different way of expressing its disapproval rather than shooting at the South Korean speakers - which it has done before - or any other direct military action.

Officials in the North may simply be trying to influence public opinion in the South, but the military in the South is interpreting the strategy as the North engaging in its own psychological warfare.

South Korea really is in a position to up the ante and is considering reinstalling huge light fixtures at the border to display messages as well as vast video screens.

'The United States should surrender its anachronistic hostile policy against the North immediately!'

The messages are clearly aimed at the South Korean public, the ones most likely to stumble upon these flyers.

One man found his car wrecked after a sack full of leaflets fell on it, while one activist who flies leaflets the other way found one lying in his front yard.

There are critics of the current president who believe more should be done to reach out to the North.

But the majority of South Koreans just don't care, even after the hydrogen bomb test claim people carried on with their daily life.

There was no panic buying, no stock market crashes. People are fairly oblivious to the leaflets, having far more important things to worry about in their busy lives.