Three Oil and Natural Gas Corporation Limited employees were allegedly abducted by “unknown armed miscreants” in Assam early on Wednesday, the company said. The police suspect that militant group United Liberation Front of Assam was behind the kidnappings, The Indian Express reported.

The Oil and Natural Gas Corporation said the employees, two junior engineering assistants and a junior technician, were kidnapped from a rig site in Assam’s Sivasagar district. They have been identified as Mohini Mohan Gogoi from Sivasagar, Ritul Saikia from Golaghat district and Alokesh Saikia from Jorhat, according to the newspaper.

“The abducted employees were taken by the miscreants in an operational vehicle belonging to ONGC,” the company tweeted. “Later, the vehicle was found abandoned near the Nimonagarh jungles close to the Assam-Nagaland border. A complaint has been lodged by ONGC with the local police.”

The crude oil and gas company added that it was in touch with the authorities. “Higher officials of the State Police are on the site,” ONGC said.

Sivasagar Superintendent of Police Amitava Sinha told The Indian Express that the manner in which the ONGC employees were kidnapped suggested the involvement of the United Liberation Front of Assam. He added, “We are suspecting ULFA because that is the only militant group active in this area.”

Sinha said the police have launched an operation to rescue the employees, according to India Today. “We have taken up the matter with our counterparts in Nagaland since the place of abduction is not far from the border with that State,” he added, according to The Hindu.