The mayor of Del Rio, Texas, has closed the international U.S.–Mexico bridge after thousands of illegal immigrants arrived in the area and set up camps underneath and around the bridge.

Del Rio Mayor Bruno Lozano, a Democrat, declared a local state of disaster and said his city is closing toll booths on the international bridge to the Mexican city of Ciudad Acuna to halt traffic, while adding that he has requested state assistance to deal with the burgeoning crisis. City officials, he said, are expecting about 8,000 more illegal aliens to arrive in the area in the coming days.

“Dire circumstances require dire responses,” Lozano said during a news conference, saying that such measures are done as a security precaution.

“There’s people having babies down there [under the bridge], there’s people collapsing out of the heat,” the mayor said. “They’re pretty aggressive, rightly so—they’ve been in the heat day after day after day.”

He added that “it’s something that [is] very challenging to describe in words, but it’s extremely chaotic.”

In all, there are about 12,000 illegal immigrants amassed around the international bridge, the mayor said. Highlighting the significant increase in illegal aliens over the past week, Lozano said there were only 2,000 under the bridge on Monday.

“We’re hearing reports that there [are] unauthorized bus systems transporting individuals to the border states” such as Texas, Arizona, California, and New Mexico, he said.

Journalists on the scene say that the majority of those assembled under the bridge are Haitian nationals who are seeking asylum amid political instability. Val Verde County Judge Lewis Owens said that he believes the vast majority are Haitian, adding that some families have been under the bridge for six days, according to The Associated Press.

Amid the crisis, Republicans in Congress have gone on the offensive against President Joe Biden, accusing him of not doing enough to prevent the surge in illegal immigration at the border. Since taking office, Biden has signed dozens of executive orders to rescind Trump-era policies, including suspending construction of the border wall.

Last month, the U.S. Supreme Court let stand a judge’s order to reinstate the Trump-era “remain in Mexico” policy, although the Justice Department said in court filings this week that discussions with the Mexican government are underway.

On Friday, Sen. Ted Cruz (R-Texas), who traveled down to Del Rio to observe, released a video from beneath the bridge. The footage showed thousands of illegal immigrants behind a metal fence.

“The reason they’re here is simple,” Cruz says in the video. “Eight days ago, the Biden administration made a political decision, a political decision to cancel deportation flights to Haiti. They did that on Sept. 8. Eight days later these numbers appear.”

“On Sept. 8, underneath this bridge, there were between 700 and a thousand people,” Cruz continued, adding: “But when the word got out that Joe Biden and Kamala Harris were no longer deporting people who came from Haiti, suddenly everyone who was here called their friends, called their family, and the numbers surged to 10,503. That’s what’s here today. It is more than the capacity of the Border Patrol to handle.”

The Department of Homeland Security hasn’t yet responded to a request for comment.

Homeland Security Alejandro Mayorkas said during an MSNBC segment Friday that the administration “will address it accordingly.”