BTS are wishing band member and “brother” Jin well as he begins his 18 months of mandatory military service in South Korea.

The K-pop group took to Twitter to share some snaps of them all posing before saying goodbye to their eldest band member.

Jin, 30, is thought to have entered service at Yeoncheon army base in the northern Gyeonggi province.

Choreographer Son Sung-deuk posted a photo of Jin with his newly-shaved head on social media, writing: “I hope you have a healthy trip and be a precious time in your life..”

Fans also gathered to say goodbye to Jin, but BTS’ Big Hit Music music label recently shared a statement urging the Army to not visit the site of the entrance ceremony.

“The entrance ceremony is a time to be observed by military personnel and their families only. In order to prevent any issues that might occur from crowding, we ask fans to please refrain from visiting the site. Instead, we ask you to keep your heartwarming words of support and farewell in your hearts,” the message included.

READ MORE: Agency Says BTS Members Will Serve In South Korea’s Military

Jin is the first of his bandmates to undertake military service.

It was revealed in October that all seven members of the popular band would serve their mandatory military duties under South Korean law, ending a debate on exempting them because of their artistic accomplishments.

Big Hit also revealed the band members were “looking forward to reconvening as a group again around 2025 following their service commitment.”

The band — its other members being J-Hope, RM, Jungkook, V and Jimin — launched in 2013. They’re currently taking a break to work on solo projects, as well as their military service.

Jin debuted his first solo single and music video for “The Astronaut”, which was co-written by Coldplay, in October.