Los Angeles Mayor Karen Bass criticized Texas Gov. Greg Abbott late Monday for busing migrants to the city as Tropical Storm Hilary drenched Southern California.

The bus departed from Brownsville, Texas, on Sunday as Los Angeles officials warned residents to brace for the dangerous and unprecedented storm, Bass said in a statement. The bus arrived Monday evening at Union Station in downtown Los Angeles carrying 37 migrants — including 16 families with 14 children and an infant — according to immigrant rights group, the L.A. Welcomes Collective.

"It is evil to endanger the lives of vulnerable migrants by sending a bus with families and toddlers on board to a city that at the time was under an unprecedented tropical storm warning," Bass said in the statement. "As I stood with state and local leaders warning Angelenos to stay safe and brace themselves for the worst of the coming storm, the Governor of Texas sent families and toddlers straight for us on a path through extreme weather conditions."

The mayor said she and her team became aware of the bus when the city's emergency operations center was activated to a higher level in response to the storm. Hilary had rolled into Southern California on Sunday, bringing heavy rainfall and risks of extensive flooding as several local officials across the region declared a state of emergency.

"If anybody understands the danger of hurricanes and thunderstorms, it’s the Governor of Texas – who has to deal with this threat on an annual basis," Bass added. "This is a despicable act beyond politics."

Abbott's office did not immediately respond to USA TODAY’s request for comment.

Immigrant rights group 'disheartened'

Monday's bus arrival is the ninth migrant bus to have been sent to Los Angeles. In a June news release, Abbott justified his decision to send migrants to the city because of its "self-declared sanctuary city status."

Abbott's press secretary, Andrew Mahaleris, told NBC News on Tuesday that "migrants willingly chose to go to Los Angeles, having signed a voluntary consent waiver available in multiple languages upon boarding that they agreed on the destination," adding: "And they were processed and released by the federal government, who are dumping them at historic levels in Texas border towns because of the Biden-made crisis. Each bus is stocked with food and water and makes stops along the trip to refuel and switch drivers."

Abbott's busing policy is part of a controversial initiative, known as Operation Lone Star, that began last year in response to President Joe Biden's border policies. The governor has also said the busing policy provides "much-need relief to Texas' overwhelmed border communities."

Since the start of the initiative, Texas officials have transported more than 30,000 migrants to Democratic-led cities across the nation, including Los Angeles, Denver, New York City, Chicago, and Vice President Kamala Harris’ residence in Washington, D.C. 

The L.A. Welcomes Collective said the migrants were transported to a receiving site in Chinatown where they were provided food, clothing, hygiene kits, health checkups, and immigration-specific legal orientations. The group also helped facilitate reunions with family members and sponsors in the region.

Of the 37 migrants, the L.A. Welcomes Collective said 20 came from Venezuela while others were from Guatemala, Mexico, Belize, Honduras, and Ecuador.

"The Welcomes Collective was surprised and disheartened to learn that Texas officials had given the green light to send this bus to LA knowing full well that the state, the county, and the city had declared Los Angeles an emergency zone amid the threat of Hurricane Hillary," the group said in a statement Monday.

Texas immigration initiative has sparked controversy, criticism

Operation Lone Star has raised numerous humanitarian concerns since the initiative began last year.

Thousands of migrants have boarded state-funded charter buses to Democratic-led cities and critics have called the initiative a political ploy that uses migrants as pawns at a cost to state taxpayers of more than $12 million.

On Aug. 11, authorities announced that a 3-year-old child who was riding a migrant bus from Texas to Chicago died in Illinois. The child's death is the first Texas has announced since the start of Operation Lone Star.

The governor has brought on new measures to the initiative, such as placing massive water buoys and miles of razor wire along the Rio Grande, which forms the border between Texas and Mexico. Last month, two bodies were recovered from the river and one was found near the buoys.

The Biden administration is suing the state over the buoys, saying the barrier in the water could lead to environmental and humanitarian problems.

POLITICAL THEATER VS. DAILY SURVIVAL:Inside the dire situation facing migrants bused across US

Contributing: Claire Thornton and Rick Jervis, USA TODAY