Transcript for U.S.-Mexico border reopens after migrants attempt to breach fence
Our guys you got to first start talking about what's going on the border you've seen some of these images now some of them are just. Haunting with what happened over the weekend a masked man has bandit with this group of people he was ever in weeks ago when he first started their walk now weeks later this is kind of what it's all been. Leading up to this clash at the border and some of what we've been seeing. I'm not sure people expected this. Or not but some of its very traumatic so Matt you wanna go check in with him now because mad as human as saying you've been here for weeks and at this clash and now is what's going on right now currently at the border. They Maggie where on the US side of the San Ysidro border here just south of San Diego. And right behind these folks coming out of that it's your right Dan way over there were people walking through they're now in the US the border into that concertina wire. And behind me some security vehicles. We've noticed additional security a probably more than normal on for this time of here we shot helicopter flying right above the 3 o'clock in the morning and I want to show you. There working on the fence right behind me I don't know if that as anything to do win. The clashes yesterday but you can see that Customs and Border Protection vehicle right there and of course that famous border fence right there that you can actually see through. Now the clashes yesterday started when hundreds of migrants began protests being 91 out. It basically wanted to be able to be allowed. To be processed for asylum. But at some point they got into these shoving matches with Mexican federal police in riot gear you can see them with the batons and those shields. And somehow they started breaking away from them they ran scampering across those canals beyond. I'll road blocks and this pick up trucks then up the canals and right to the concertina wire work. US Customs and Border Protection. Opened up this fusillade of fire using up pepper balls which are non lethal and tear gas canisters to try to drive them away. And you know. Caught in that cloud of of CS gas where women and children and many of the migrants who've been part of this procession out. We join the procession. Way back in Mexico a month ago. And it was very peaceful non. People had marched a few hundred miles just. By foot. Across. The border from Guatemala to Mexico that part was not peaceful XT burst through the fence there and had to be driven back but afterwards up for many hundred miles a that's 2400 miles from. Doppler chula Mexico two T one there was not a single violent incident that we know of and say oh it seemed to be a completely passive. Event and it managed to go to 2400. Miles from topic to a Mexico all the way to T one a without any major incidents now we're just. Show you again at the Border Patrol they are definitely on garden you can see them. Right at the fence right there and there apparently talking to. Somebody looks like. Mexican kids with backpacks. On the other side of the border there. To deathly an increased sense of security here in the US side now the big threat has been from president trump who said that if additional violent clashes occur today you'll completely shut down. This border terminal now it's very quiet now is it's up pretty early in the day here but it can get incredibly busy especially. The road traffic terminal mats were all these thousands and thousands of cars pass today this is the busiest border terminal on told. In the world more people cross back and forth through here than anywhere else on it was incredible is that you know we arrived here very very early in the morning for Good Morning America. 2 o'clock in the morning and they're still people go to work or coming back. A tremendous amount of activity here and if this place is closed down. It would cause enormous. Chaos in this part the border between Mexico and the US now. At this board about 5000. Migrants on the other side of the border in Tijuana that number set to swell to 9000 according to caravan organizers over the coming days. And that border terminal from what we know and from what Customs and Border Protection tells us. Can only accommodate about 100 people. Per day so you do the math and it could take very many days up to months to process every one. In the question is. How will what that processing go -- be slow footed we just simply don't know at this point but it is. US law that they basically have to. Evaluate each person's. Asylum request. They don't have to granted but they the US government does. And is obligated to evaluate everybody's request and typically when they do that people are on the US side of the border that is something to present from. Does not want to see. So lots more to come here both from this side of the border and of course the next gets out of the border. In the coming days.
This transcript has been automatically generated and may not be 100% accurate.