The US state of Alabama has passed into law one of the most stringent immigration laws in the country.
The new law, similar to one passed last year in Arizona, requires schools to find out if students are there illegally, and also makes it a crime to give an illegal immigrant a ride in a car.
Advocacy groups say they will challenge the law, which they call racist and unconstitutional. An attorney for the American Civil Liberties Union says it could deter some immigrant parents from sending their children to school, for fear of arrest or deportation.
There are an estimated 12 million illegal immigrants in the US - and individual states have increasingly taken matters into their own hands in an attempt to tackle the problem.
But none has gone as far as Alabama, the BBC's Washington correspondent reports.
As in Arizona, police will now be allowed to arrest anybody suspected of being an illegal immigrant - even if they are stopped for something else.
Inn addition, businesses and schools will be required to check the legal status of workers and students, while landlords will be committing a crime if they knowingly rent to illegal immigrants.
Governor proud of legislature
Republican governor Robert Bentley, who signed the bill into law on Thursday, said: "We have a real problem with illegal immigration in this country.
"I campaigned for the toughest immigration laws, and I'm proud of the legislature for working tirelessly to create the strongest immigration bill in the country."
The law takes effect on 1 September,
A district judge earlier blocked the most controversial parts of the legislation - such as wider police stop-and-search powers - amid fears of racial profiling.