AUSTIN, Texas — The Mexican government, San Antonio’s police chief and others slammed Texas’ new “sanctuary cities” law on Monday, saying that requiring local law enforcement to help enforce U.S. immigration law could lead to racial profiling and will fan distrust of the police by the state’s many Hispanics.

The law, which takes effect in September and which critics say is the most anti-immigrant since a 2010 Arizona law, will allow police officers to ask about the immigration status of anyone they detain, including during routine traffic stops. Republican Gov. Greg Abbott signed the law Sunday evening on Facebook Live with no advanced warning. A few dozen people protested outside his mansion in Austin on Monday.

San Antonio police chief William McManus ripped into the Republicans who pushed the law through despite the objections of every big-city police chief in the state. The Migration Policy Institute estimates that Texas is home to more than 1.4 million people who are in the country illegally, including 71,000 living in the San Antonio area.

McManus and the other police chiefs, including those in Dallas and Houston, say it will create a chilling effect that will cause immigrant families to not report crimes or come forward as witnesses over fears that talking to local police could lead to deportation. Critics also fear it will lead to the racial profiling of Hispanics and put officers in an untenable position.

“It’s either skin color or language. What else does someone have to base it on?” McManus said, referring to an officer’s reason for inquiring about a person’s immigration status. “That leads to profiling. Profiling leads to lawsuits. In my opinion, there is nothing positive this bill does in the community or law enforcement.”

Nevertheless, McManus said his department will abandon a policy that prohibits officers from asking about a person’s immigration status.

“We’re going to have to take it off the books,” said McManus, adding that it will probably have to spend a year now training his roughly 2,400 officers on immigration law.

The law also drew rebuke from Mexico, which is Texas’ largest trading partner and shares close ties to the state. The country’s foreign ministry said in a news release that the law could trample on the rights of Mexican citizens who choose to live just across the border and promised to “closely follow” the situation after the law takes effect.

“These types of actions criminalizes even more the topic of immigration, foments racial discriminatory acts and reduces collaboration between the immigrant community and local authorities,” the ministry said.