South Korea has demolished a Christmas tree tower at the tensely-guarded border, a defense official said Wednesday, removing a recurring source of inter-Korean conflict amid hopes of a thaw in ties.

In an annual Christmas ritual, South Korea used to cover the metal tower on Aegibong hill near the western front-line border area with colorful lights as part of propaganda efforts against North Korea. The tower could be seen as far away as the North Korean border town of Kaesong.

The practice has been a recurring source of diplomatic and military tension with the North, which once threatened to shell the tower.

But the removal of the tower last week was carried out purely in consideration of the rising risk of collapse, the defense official said.

"The maintenance team of the defense ministry conducted a safety check on major military facilities last November and the Aegibong light tower was given a D grade," the official said, refuting any speculation that the demolition had anything to do with inter-Korean relations.

The official said that the tower was at risk of collapse in case of strong winds or other physical pressure. 

But some experts speculated the government may have considered the burgeoning reconciliatory mode between the rival Koreas. 

North Korea's surprise dispatch of high-level officials including Hwang Pyong-so, known as the second-most powerful man in North Korea after leader Kim Jong-un, to the closing ceremony of the 2014 Incheon Asian Games earlier this month was a major breakthrough in the long frosty inter-Korean ties.

They are in the process of arranging another round of high-level inter-Korean talks.

Since being built in 1971, the tower was lit annually during the Christmas season until Seoul and Pyongyang agreed in a military dialogue to stop propaganda activities at the border areas in 2004.

Seoul, however, resumed the ceremony in 2010 after the North's sinking of the South Korean Navy corvette Cheonan in March of the same year. (Yonhap)