The U.S. military started to move parts of is controversial THAAD anti-missile defense system to South Korea amid growing tensions with North Korea. The move sparked protests by locals and prompted criticism by South Korea's front-runner Moon Jae-in in the presidential elections. The U.S. and South Korea agreed to deploy the defense system last year in response to missile launches carried out by North Korea. There was no word as to why the battery installation was started in the dead of night.