Four women have been arrested and indicted on 30 felony counts of voter fraud in the 2016 election.

The women were paid to harvest mail-in ballots from senior citizens in North Fort Worth, a statement from the Texas attorney general's office claims.

The voter fraud ring forged some signatures and lied to obtain others, edited old applications and resubmitted them without the voters' knowledge, according to the office.

Many of the voters had to cancel their ballots to vote in person.

Each of the women faces felony charges of providing false information on an application for a mail ballot: 16 counts for Leticia Sanchez, 10 for Leticia Sanchez Tepichin, two for Maria Solis and one for Laura Parra. Sanchez also faces one count of illegal voting.

"Ballots by mail are intended to make it easier for Texas seniors to vote," Attorney General Ken Paxton said in a prepared statement. "The unfortunate downside is their extreme vulnerability to fraud."