Three employees of India’s Oil & Natural Gas Corporation (ONGC) have been abducted from an onshore drilling site at its Lakuwa oilfield in Assam’s Sivasagar district.

The state-controlled giant said “the abducted employees were taken by the miscreants in an operational vehicle belonging to ONGC” on the morning of 21 April.

The company said it has lodged a complaint with the local police and the “local administration has been informed about the incident".

United Liberation Front of Assam (Independent) (ULFA-I) — a banned separatist group that operates in the northeastern part of the country, is said to be behind the abduction, several media reports have claimed.

The vehicle used for the abduction was later “found abandoned near the Nimonagarh jungles close to the Assam-Nagaland border", ONGC said.

Of the three employees, two are junior production technicians, while the third is a junior engineering assistant working with ONGC.

The employees have been identified as Mohini Mohan Gogoi from Sivasagar district, and Alakesh Saikia and Retul Saikia from Jorhat district, according to local media report.

Amitava Sinha, the superintendent of police of Sivasagar, said the force has asked for security agencies in the nearby state of Nagaland to be on a high alert.

“Nagaland is very close to the actual location of the incident — the vehicle was found abandoned near the Nagaland border. So, police in Nagaland’s Mon district has also been activated,” he was quoted as saying.