By , SINGAPORE/NEW DELHI (Reuters) - In the days leading up to the most violent border clash between India and China in decades, China brought in pieces of machinery, cut a trail into a Himalayan mountainside and may have even dammed a river, satellite pictures suggest.The images, shot on Tuesday, a day after soldiers engaged in hand-to-hand combat in the freezing Galwan Valley, show an increase in activity from a week earlier.India said 20 soldiers were killed in a premeditated attack by Chinese troops on Monday night at a time when top commanders had agreed to defuse tensions on the Line...…By , SINGAPORE/NEW DELHI (Reuters) - In the days leading up to the most violent border clash between India and China in decades, China brought in pieces of machinery, cut a trail into a Himalayan mountainside and may have even dammed a river, satellite pictures suggest.The images, shot on Tuesday, a day after soldiers engaged in hand-to-hand combat in the freezing Galwan Valley, show an increase in activity from a week earlier.India said 20 soldiers were killed in a premeditated attack by Chinese troops on Monday night at a time when top commanders had agreed to defuse tensions on the Line...WW…