Riot police stand guard on the street as Trump visits a nearby hospital for treating shooting injured persons, in El Paso, Texas, the United States, Aug. 7, 2019. U.S. President Donald Trump and First Lady Melania Trump on Wednesday afternoon visited the University Medical Center and the Emergency Operations Center in the city of El Paso in the U.S. state of Texas, where they were greeted by protesters. The visits came just days after two mass shootings took place hours apart over the weekend in the United States, leaving at least 31 people dead and dozens injured. (Xinhua/Wang Ying)