Mexicali, Baja California — Dressed in matching white suits and holding hands on as they stepped into City Hall, Fernando Urias Amparo and Victor Manuel Aguirre Espinosa hoped to make history as the first same-sex couple to be legally married in Baja California.

But after hours of uncertainty — and one year and seven months after their initial attempt — the pair walked out disappointed, having been turned down once again by city officials.

Despite an order from the Mexican Supreme Court this year that cleared the way for the couple’s marriage, authorities with the Mexicali civil registry said paperwork problems prevented them from carrying out the ceremony.

"When they bring it all completed, we’ll accept the petition," said Jose Felix Arango Perez, Mexicali’s secretary-general, after a tense meeting with the couple and their supporters.

Urias, 37 and Aguirre, 43, both hairstylists, say they first fell in love 10 years ago after meeting in a bar. They share a passion for Flamenco dancing, a three-bedroom house with two dogs, and work in the same salon owned by Aguirre near the international border fence with Calexico. They say they both come from large and loving families and dream of raising a child of their own.

The uncertainty of recent days "has been like a roller-coaster ride," Aguirre said during an interview in his salon last Thursday. "There are many mixed feelings, and I think tomorrow they’re all going to come out."

As they arrived at City Hall on Friday, surrounded by family members and friends, they walked past a dozen Catholic opponents of same sex marriage who held signs and prayed. Once inside the Civil Registry offices, a registry official told them that she had not been told of the ceremony, that she could not perform the marriage, and no one was available to provide an explanation.

A couple of hours later, officials announced a bomb threat at City Hall, evacuating the entire building just as the couple’s attorney, Jose Luis Marquez, and the witnesses prepared for a private meeting with the city’s legal department to discuss what was holding up the ceremony. They were all told to report back at 2:30 pm, and when they did, they were told that the wedding could not proceed.

The head of the Civil Registry office, Guadalupe Adriana Nevarez, said there were inconsistencies in the signatures of two of the witnesses, and that there was problem with a federal identification document. The couple and their supporters said the city’s position was simply the latest example of the city’s unwillingness to perform a same-sex ceremony, and making demands that are not required of heterosexual couples.

"These are dirty strategies," Urias said. "They are not respecting a federal order."

Gay marriages have been performed in Mexico since 2010, after Mexico City revised its civil code to permit same-sex marriage. Last September, a state legislature followed suit in the northern border state of Coahuila, across from Texas.

But in Baja California and elsewhere in Mexico, gay marriage advocates have been fighting their battles through the court system, with individual couples petitioning for the right to marry, some winning their cases only after appealing them all the way to the Supreme Court. Forging the way were three same-sex couples from Oaxaca, who won the court’s backing in 2012, and were able to wed the following year.

Alex Ali Mendez, an attorney who heads a coalition called Matrimonio Igualitario Mexico, has played a key role in many of these victories. Conducting gay marriage campaigns is difficult in Mexico, he said in a telephone interview. "All of the conservative religious strain makes it difficult to get support from civic groups or to receive financial backing from private ones."

Mexico’s attitudes toward gay rights are complex and sometimes contradictory, he said. "On the one hand, there is tolerance, but legal rights are not tolerated."

The victory of one same-sex couple does not automatically open the door for others in the same entity, Mendez said. Only after five similar rulings would a state find itself basically forced to open the door to all same-sex couples, and the individual battles can be prolonged and costly.

Since the legal victories of the first three Oaxacan couples, Mendez has been testing a range of other legal tactics. One involves a group of 39 gays and lesbians — not necessarily couples — in the state of Oaxaca that in April won the Supreme Court’s backing for a collective action giving them right to marry should they choose to do so. A group in Baja California is now planning the same collective action with 150 people, said Andres Cruz Hernandez, leader of a Tijuana-based gay rights group, Cocut.

Mendez also has been working with Urias and Aguirre in their quest to be married. "Being the first couple, they always face more obstacles," Mendez said. "It wears on them. There is always a psychological cost."

The couple and their supporters left angry and frustrated, but said they were not giving up. It was unclear how long it would take to clear up the paperwork issues, but they were prepared to try again. And in the meantime, they didn't cancel their party planned for Friday night.

"We are going to continue celebrating, I have all my family and friends here," Urias said. City officials "are not going to ruin the day."