MARIETTA, Ga. — Election officials in Georgia’s third-largest county said they were late sending more than 3,000 absentee ballots to voters just days before the election.

Election officials in Cobb County, north of Atlanta, were using U.S. Postal Service express mail and UPS overnight delivery in an effort to deliver ballots on time. Mail-in ballots must be returned by Election Day on Tuesday in order to be counted.

“We want to maintain voters’ trust by being transparent about the situation,” County Board of Elections Chair Tori Silas said Thursday. “We are taking every step possible to deliver these ballots to voters who request them.”

Silas blamed the delay on faulty equipment and a late surge in absentee ballot requests in the week before the Oct. 25 deadline.

Late ballots were mailed in prepaid express return envelopes, and election officials said they would ensure they were returned on time.

Georgia voters have broken early turnout records since primary voting began Oct. 15. As of Thursday, more than 3.6 million ballots had been cast, representing more than half of the state’s active voters, according to Georgia Secretary of State Brad Raffensperger’s office. This number includes more than 226,000 absentees.

In Cobb County, election officials said voters with delayed outstanding ballots can vote in person on the last day of early voting on Friday or Tuesday. The county’s election center planned to remain open to accept hand-delivered ballots over the weekend and Monday.

But the Board of Elections said more than 1,000 late-mailed ballots were sent to people outside Georgia.

County spokesman Ross Cavitt declined to comment Friday on which, if any, late ballots should be mailed, citing ongoing litigation.

Two civil rights groups, the American Civil Liberties Union and the Southern Poverty Law Center, filed a lawsuit Friday asking a Cobb County judge to extend the deadline for counting absentees stamped by Election Day to three days later, Nov. 8.

The complaint was filed on behalf of three Cobb County voters who said they still had not received a mail-in ballot as of Friday. Although county election officials “took some steps to help alleviate the problem, these actions were not nearly sufficient to protect voting rights,” the lawsuit said.