AUSTIN, Texas — At least 12,000 migrants are camped out under the U.S. side of an international bridge that connects Mexico to Del Rio, Texas, as of Friday morning, as more noncitizens streamed across the border river overnight, according to a federal law enforcement official on site.

“First thing this morning, it was over 11. And now we’re nearing — it’s over 12,” said Jon Anfinsen, a Border Patrol agent who is president of the National Border Patrol Council’s Del Rio chapter, referring to people in the thousands. “It’s now essentially a small city.”