Hundreds of Honduran migrants have crossed the Guatemalan border as they travel in the direction of the United States.

The group that reached Guatemala yesterday is the first wave of a caravan that could consist of thousands. It’s the first national border crossed by the migrants on their journey that started Monday night.

Some migrants told reporters they were looking for new opportunities in the U.S. Some said they were fleeing violence. But no matter their reason for seeking a new life, they have already become symbols in the ongoing battle between President Trump and Congressional Democrats over border security as the government shutdown enters its 26th day. President Trump seized on news of the caravan as another reason to fund his proposed border wall.

“A big new Caravan is heading up to our Southern Border from Honduras,” Trump tweeted Tuesday. “Tell Nancy [Pelosi] and Chuck [Schumer] that a drone flying around will not stop them. Only a Wall will work. Only a Wall, or Steel Barrier, will keep our Country safe! Stop playing political games and end the Shutdown!”