A Russian woman who was kidnapped in northeastern Mexico has been released, Russian embassy and Tamaulipas state officials said Sunday.

The woman, whose identity has not been revealed, was released without paying the ransom kidnappers sought and was taken to a police station in Reynosa, Tamaulipas state, near the U.S. border, diplomats said on social media.

She was rescued “in good health” late Saturday by a state anti-kidnapping unit, police said. They provided no details on how the rescue took place, who the captors were and whether they had been arrested or killed.

The woman was believed to have been abducted while traveling with Mexican acquaintances between Monterrey, in Nuevo Leon state, and Reynosa.

In March last year, people believed to be with a criminal group known as the Gulf Cartel kidnapped four Americans in Tamaulipas in an incident that left two of them dead.

Americans Zindell Brown and Shaeed Woodard died in the attack; Eric Williams and Latavia McGee survived. A Mexican woman, Areli Pablo Servando, 33, was also killed, apparently by a stray bullet.

The Gulf drug cartel turned over five men to police soon after the abduction. A letter claiming to be from the Scorpions faction of the Gulf cartel condemned the violence and said the gang had turned over to authorities its own members who were responsible. 

In January, Mexican marines detained one of the top leaders of the Gulf cartel.

Tamaulipas is among the states hardest-hit by violence linked to organized crime such as drug trafficking and kidnapping. The state is also a busy route for undocumented migrants hoping to cross into the United States.

Last month, Mexican troops on patrol killed 12 gunmen in a clash near the U.S. border in Tamaulipas.

The Associated Press contributed to this report.