Civil rights groups intensified their legal fight against the US state of Georgia's new voting restrictions with a third federal lawsuit.
Meanwhile, Delta Air Lines and Coca-Cola, based in Atlanta, continued to face boycott calls from activists who said they must to do more to oppose the law.
The Republican-backed law, which Governor Brian Kemp signed last week, toughened ID requirements for absentee ballots and gave politicians the power to take over local elections.
It limited the use of ballot drop boxes, shortened early voting periods for run-offs and made it a misdemeanour for members of the public to offer food and water to people waiting in line to vote.
The lawsuit filed in US District Court in Atlanta late on Monday called the law racially discriminatory and "an attack on democracy".
"This law is voter suppression, plain and simple, and aimed at making it harder for black and brown and other historically disenfranchised communities to have a voice in our democracy," said Sophia Lakin, of the American Civil Liberties Union.
"It is an absolutely shameful response to the historic participation by these communities in the last election cycle."
The union, the Southern Poverty Law Centre and the National Association for the Advancement of Coloured People's Legal Defence and Educational Fund filed the latest lawsuit on behalf of several grassroots groups.
They included the Sixth District of the African Methodist Episcopal Church, made up of more than 500 churches in Georgia, and the historically black sorority Delta Sigma Theta.
The state already faces two similar lawsuits brought by civil rights groups over the law.
Mr Kemp's office declined to comment on the pending litigation.
Republican politicians in other political battlegrounds, including Florida and Arizona, are also seeking voting restrictions.
The say the limits are aimed at curbing fraud but research shows voter fraud is exceedingly rare in the US.
Delta and Coca-Cola have faced boycott calls on social media from critics who say they have not taken a forceful enough stand against the restrictions.
"While we are disappointed in the outcome, we don't see this as the final chapter," Coca-Cola said on Monday.
The company said it would "continue to press for improvements to Georgia's election laws in future sessions".
Delta chief executive Ed Bastian on Friday said the airline had "engaged extensively with state elected officials in both parties to express our strong view that Georgia must have a fair and secure election process", and that the legislation "improved considerably" during deliberations.
"Nonetheless, we understand concerns remain," Mr Bastian said.
In an open letter on Monday, Bernice King, daughter of assassinated civil rights leader Martin Luther King Jr, criticised the Atlanta business community for its "shocking silence", especially after last year's Black Lives Matter protests and civil unrest.
The letter was also signed by the children of two other civil rights leaders, John-Miles Lewis, son of the late congressman John Lewis, and Al Vivian, son of the late Rev CT Vivian.
Democrats won Georgia in November's presidential election for the first time in decades, and then followed it up by sweeping two US Senate races in January, giving them narrow control of Congress.
Republican former president Donald Trump has claimed falsely that his loss to Democratic President Joe Biden was because of massive voter fraud, including in Georgia.
State recounts found no significant irregularities.
