(CNN) -- At least 16 migrants, including a woman, were being held for ransom by human smugglers in Tijuana, Mexico, according to a migrant who was freed, authorities said late Wednesday.
"With respect to the man, we are not releasing his name but he is between 20 and 25-years-old. We can tell you that his family paid a ransom for his liberty and it was after that he came to us and told us there were others that were being held in Tijuana," Municipal Police Officer Jose Varela told CNN by phone.
It was unclear how much the family paid, but reports from local journalists said the fee for freedom was $4,500.
Varela could not confirm that to CNN, but said, "that sounded right."
"We don't know who is responsible for the kidnapping, but it's likely tied to drug traffickers," Varela said.
The whereabouts of the other migrants was unclear, but the migrant who was released said they were "bound by both hands and feet," according to the police.
Tijuana is about 20 miles (32 km) south of San Diego, California. The Mexican city saw a surge of drug-related violence in 2008 and was the site of some of the bloodiest gunbattles between rival factions of a drug cartel.
In January, Teodoro "El Teo" Simental, a man who police say was responsible for much of the violence in Baja California, was arrested by Mexican federal police in the coastal town of La Paz, Mexico.
The main cartel in Tijuana had been the Arellano Felix Cartel, which by most official estimates has been severely weakened -- if not altogether dissolved -- during President Felipe Calderon's nearly four-year-old war on organized crime.