North and South Korea exchanged fire across their land border on Friday, as the North Korean leader Kim Jong-Un missed another key political event

North and South Korea exchanged fire across their land border on Friday, as the North Korean leader Kim Jong-Un missed another key political event, extending a month-long absence.

"There was an exchange of fire," an official at the South’s Joint Chiefs of Staff office said, without elaborating.

There were no reports of any casualties, Agence France Presse reported.

Meanwhile on Friday, the Northern leader, believed to be 30 or 31, has not been seen since September 3 when he attended a music concert with his wife in Pyongyang.

Kim was not listed by the state KCNA news agency among the officials who visited the mausoleum housing the remains of his father and grandfather -- an annual show of respect to mark Friday's anniversary of the ruling Korean Workers' Party foundation.

Kim's absence from the Kumsusan mausoleum visit was considered significant as he has attended each year since coming to power following the death of his father in 2011.

While he could still make an appearance later in the day, a complete no-show will likely send an already whirring rumor mill into overdrive.

Kim, a heavy smoker, has shown striking weight gain over the past year and recent TV footage had shown him walking with a pronounced limp.

Earlier, dozens of members of the Seoul-based “Fighters for a Free North Korea” had sent around 200,000 leaflets across the heavily-fortified border attached to 10 giant, gas-filled balloons.

Seoul allowed the exercise, which coincided with the 69th anniversary of North Korea's ruling party, to go ahead despite warnings from Pyongyang of "catastrophic" consequences.