The office was opened with great fanfare in September 2018

North Korea has blown up its joint liaison office with the South near the border town of Kaesong, South Korean officials say.

The move comes just hours after the North renewed threats of military action against the South.

The site, which is in the North's territory, was opened in 2018 to help the two Koreas to communicate.

The liaison office has been empty since January due to Covid-19 restrictions.

Tensions between North and South Korea have been escalating for weeks, prompted by defector groups in the south sending propaganda into the north. 

The North Korean leader's sister, Kim Yo-jong, threatened to demolish the office in a "tragic scene" in a statement at the weekend.

The two states set up the office after talks between North Korean leader Kim Jong-un and his counterpart from the South, President Moon-Jae-in. BBC