Sixteen police employees who had been kidnapped in Mexico's southern state of Chiapas have been freed after three days of captivity, governor Rutilio Escandon said.

"I want to tell the people of Chiapas and Mexico that the 16 kidnapped colleagues from the [Security Secretariat] have been released this afternoon," the governor said on Twitter on Friday, while TV stations aired live footage of the abductees reuniting with their families.

"All of them are OK," a spokesperson for the security ministry said.

The relatives had been staging a sit-in at the Chiapas Security Secretariat, demanding the safe release of their loved ones.

As the newly freed police workers approached on foot, the surprised family members raced to embrace them amid screams and tears, news footage from Foro TV and Milenio showed.

One woman was shown sobbing, yelling out, "Thank you Lord!"

More than 1,000 members of state and federal security forces were involved in the search for the workers, who are administrative employees of the police force.

They had been kidnapped on Tuesday while travelling on a stretch of highway that connects the town of Ocozocoautla and the state capital Tuxtla Gutierrez, some 700 kilometres southwest of Mexico City.

The kidnapped employees were recorded in a video shortly after going missing, eyes cast to the ground, standing together, as one gave a message that they would be freed in exchange for resignations from ministry higher-ups.

The motive of the kidnapping as well as the conditions of their release remain unclear.