Police on Saturday apprehended a university student who allegedly posted an online message threatening a terror attack on the home of President Yoon Suk-yeol.

The man in his late teens was nabbed on the southern island of Geoje, about 400 kilometers south of Seoul, the Seocho Police Station in Seoul said.

The student, currently on leave of absence, told police he posted the threat in anger over Yoon's breach of his campaign pledge to more than triple conscripted soldiers' salaries.

The suspect is likely to be released soon as the act is not a serious crime, the police station said.

The post was uploaded on an online fan community for first lady Kim Keon-hee on Thursday afternoon, threatening to launch a terror attack against Yoon's private home in southern Seoul at 6 a.m.

Friday.

After it was reported to the National Intelligence Service, the police beefed up security around Yoon's home, including deploying police commandos.

During his campaign, Yoon promised to raise the monthly wages of enlisted service members to 2 million won (US$1,598). Currently, a sergeant receives 676,100 won per month.

But after his election, his transition team backed down from the pledge, offering instead a slight wage hike and a lump sum payment upon discharge.

Since taking office May 10, Yoon has been commuting between his private home and the presidential office in Yongsan, central Seoul.

He relocated the presidential office from Cheong Wa Dae to the former defense ministry building, in line with his campaign pledge to come closer to the people. Yoon plans to move into a new official residence that is being renovated.