Officials in Oaxaca, Mexico, rejected applications by 17 male candidates who tried to register as transgender women in the upcoming summer elections. Authorities said the applications, from various parties, were rejected due to “suspected irregularities.”

Oaxaca requires gender party in local races, but according to Reuters, various parties had been unable to find enough female candidates, so they filled the available slots with men claiming to be transgender.

“[We] will be vigilant that the constitutional principle of equality is adhered to and that women have effective access to public office,” officials said.

The men were running for mayor and assistant mayor in the region, but the electoral council may keep them off the ballot now and fine their parties.

Oaxaca has a centuries-old tradition of non-binary people, known as muxes, who are often considered a third gender. It was the muxes community who brought the fraud to the attention of election officials, claiming that only two of the 19 candidates who registered as trans were part of their community.

“The majority of them have publicly known marriages and children with women,” a coalition of muxe and women’s rights groups said in a statement. “Some of them are even running for re-election as mayors, and during their past terms they said nothing about being transgender.”

“We reject this fraudulent usurpation of trans identity meant to avoid the obligation of the parties and the candidates to respect the constitutional mandate of gender equality," they added.

Mexicans will vote for president and thousands of local positions on July 1.