A total of 12 transporter erector launchers(TEL) carrying a Hwasong-17 intercontinental ballistic missile(ICBM) were present during North Korea’s armed forces anniversary parade last Wednesday.

According to analyses by experts of North Korea's press photos of the parade and foreign commercial satellite images on Sunday, eleven units were included in the procession.

A 12th one, presumed to be a spare unit prepared to replace one of the eleven participating TELs in the event of a malfunction, could be detected in photos published by the North's state media.

Shin Jong-woo, the secretary-general of the Defense Security Forum in South Korea, said Pyongyang readies a spare vehicle to guarantee a flawless parade, as seen in preparations for last year's ruling party anniversary.

In 2014, South Korean military and intelligence authorities had speculated that the North likely possessed around 100 TELs.