>> Playing cat and mouse with border agents in Mexico. Reuters capturing footage of migrants from Central America huddled in the shadows, waiting for their chance to leap onto a cargo train headed north. But with Donald Trump in the White House, their ultimate destination, the Mexico-US border, is a window of opportunity that may be closing.
>> We're in search of the American dream, this is our goal. The struggle is getting there.>> The migrants face growing risks as they make their journey north. Mexico beefing up its own border forces, last year arresting nearly 150,000 migrants, from countries like Guatemala, El Salvador, and Honduras.
Experts say many are running from poverty and gang violence, and their numbers are surging, as people try to squeeze in before the new US president makes good on his campaign promises.>> If that man Trump ends up building a wall or has 5,000 more border agents, then it's going to get a lot tougher to get in.
>> The US detained more than 400,000 people along its southwest border with Mexico last year, a 25% jump from the year before, the vast majority from Central America.