The Defense Department is ramping up resources at the US-Mexico border as officials describe a surge in border crossings in places including Eagle Pass, Texas, where the mayor has declared a state of emergency.

Some 800 new active-duty personnel are being sent to the border, where 2,500 National Guard members already are serving, Department of Homeland Security officials announced Wednesday night in a call with reporters.

The move comes as migrant crossings along that border are rising, surpassing 8,600 over the last 24 hours, according to a Department of Homeland Security official. That’s up from around 3,500 daily border arrests after the expiration in May of Title 42 triggered new consequences for those who cross the border illegally. There were than 8,000 apprehensions on Monday.