Commemorations are being held in South Korea to mark the 60th anniversary of the outbreak of the Korean War. At a ceremony in Seoul, President Lee Myung-bak paid tribute to visiting veterans, including UK and US troops. North Korean tanks and troops swept south on 25 June 1950, starting a three-year conflict that claimed an estimated three million lives. The US led the United Nations in support of the South while China and Moscow backed the North. The war ended with a ceasefire rather than a peace treaty, leading to almost constant political tension ever since. North Korea still disputes the widely-held view that it attacked first.